But there are some limits. It depends of the case.
This is all getting a little bit muddy in terms of the connection between the creator and the finished work.
The initial comment I made is that if you liked Y you'll probably like X.
Your initial counter argument was that X and Y are very different shows in terms of genre, setting etc and so there's no reason to assume that a person who likes Y would naturally like X.
I responded my explaining my original point, namely that you'll probably like this one work (X) because it's was made by the same people as another work (Y) which you have already enjoyed. The assumption here being that part of the reason you liked Y is because of the people who put it together, irrespective of the actual genre of the piece.
Moreover, to focus solely on bare content e.g. genre and setting misses the fact that we can like art because of the people who make it irrespective of what final shape the art takes, and I provided some examples of directors that people will follow to see what they do next even without knowing what form their work will take.
When the author is an individual, like an author book or a mangaka, I think it's more normal to do recommendations by author, as the work is fully theirs. Another example, music bands. Not an individual! But with music bands, the number of authors is smaller so there is more coherent and authorial output and well, usually music bands usually move themselves in the same genre (jazz, progressive metal, rock & soul, rap, pop) that's why you usually can check a group past albums if you liked one of them. Chances are very high that you will like one if you liked other.
Imo, it is a bit more weird with a production group than in the end it's a company, and companies sometimes will produce something original, or are hired to make an adaptation, whatever.
Obviously the closest you can get to a creator is with something that comes solely from them e.g. a piece of writing (ignoring the existence of editors), a painting, whatever. Once you bring in any work that requires a team (whether it be large or small) to produce you've obviously diluting the connection between the 'original' creator and creation. There's also the question of whether the people working on this team project are just blindly implementing the will of the 'creator' or are they contributing their own ideas and thoughts to the project? It surely depends on a case by case basis.
Even with large teams of people making e.g. a movie or TV show you can still feel the hand of the creators e.g. a David Simon TV series or a Miyazaki movie. They breath life into the entire work even though their ideas are transmitted and changed by many people.
So, to look at it as the case of these two anime shows it's pretty clear that the same overall director directed both shows and his style is inherent both to the look of the show, the writing, the methodical and slow pace, as well as the writing in general. The traits that make one show good bleed into the other. The actual setting etc is irrelevant to what makes those shows
good. And they are good because of the people who make them, which is why I'd recommend people check out works from the same creator.
Let's look at it from another angle. If I'm just just talking out of my ass and what's important isn't the creators (which I've already established are much the same between the two works) but instead the genre, setting and characters lets compare some works with the similar genre's, setting and characters.
If you like this complex cyber police thriller you should buy this slow paced fantasy adventure!
That's a weird comment to make. Of course someone can like both series, but in the same way people could easily like one and not the other.
The setting, genre and character focus are different in the two series!
To use your words, lets compare a few "complex cyber police thrillers". Heck, lets make it easy and just look at one franchise:
Ghost in the Shell.
This is a pretty big franchise now with works like the
Ghost in the Shell movie,
Ghost in the Shell Stand Alone Complex the TV series and
Ghost in the Shell: Arise the OVA series. Do you imagine that all these works are really similar just because they share the same genre and setting and characters? And that therefore being fans of one would lead to being fans of the others? Well you'd be wrong because in fact all these works are very different with plenty of people who like one despising the others. What's the difference between all these works? The creators.
Following your example, yeah, I also wouldn't recommend to buy a movie blindly because someone liked another movie altogether from the same director. You liked Schindler's List? You should totally buy Jaws and War of the Worlds!
Maybe you should, they're all pretty good movies. And are you actually suggesting people don't operate like this in reality? That they don't follow directors they like? In fact, it's not even that complicated (as marketing has shown us), people will just go and watch whatever movie their favourite actor/actress is in, a factor which has very little to do with the final work! But it would be odd to expect people to act differently.
Nor I would recommend to buy Moribito if you liked Ghost int he Shell, and I've seen both. Hell, if I had to make a blind guess, I would say the chances of liking it if you liked Gits are "less than average chances", no "more than average chances".
Leaving aside hypotheticals, doesn't it make more sense to operate with some guiding principle e.g. do I like the people who are making the show? Have I seen their work before? Was it good?
The alternative you propose of genre, setting and character is surely more unusual. Should people watch every high school romance because they liked one once? Surely the reason why they like one was because of the creators who worked on it, not because it was a high school romance.
Surely the reason they liked
Ghost in the Shell: Stand Alone Complex is because it's a great anime produced by talented people, not because it's a complex cyber police thriller. I'd rather tell people who liked
Stand Alone Complex to watch
Moribito then watch
Psycho Pass because it's in the same genre.