Just saw the episode and I absolutely hated it.
Sorry that Ash vs Evil Dead isn't working for you. Not everything is going to be universally loved sadly.
The second it was revealed what started the outbreak, I suddenly became unhappy and it only went worse from there. From cringe comedy (which is already a crippling quality to have), to the atrocious effects, to the boring characters and awful dialogue, to the mindblowingly terrible premise, to the forced Evil Deadisms, not one thing after the intro brought me joy.
The cringe comedy and cheesy dialogue are just staples of Raimi's style. The man is a Three Stooges fanatic and its influence is practically in everything he does. The Evil Dead series are great for the quips but in all seriousness the moment to moment dialogue had always been cheesy. That's just part of its charm. No different here, but I actually think that moment to moment dialogue has improved a bit since the movies. "Give me some sugar baby" from AoD is a fun line, but if you start to look at the context of how and when it is said it can come off as very forced and awkward.
Those "forced" Evil Deadisms have been a part of each of the previous movies. From the unseen force, to the rocking chair, to the "unpossessed" partner, to Ash beating himself up in some fashion, these have all been present in some form or fashion in each of the movies. Why should they be missing here too?
For me the lack of constraint led the show to have goals that it couldn't reach, there was no way that they could have afforded to have the scenes done as well as they wanted to. A subdued approach could have built up the situation and characters better while hiding the budget, but it had to be loud and out there.
Here is probably why you are getting the "you don't understand" comments to your criticism, and I'm sorry if this comes off as the same. Evil Dead has always been a series where they've had low budgets and shot for the skies. Could more of a budget helped with the effects in these movies? Of course! But they didn't have that money so they did whatever it took to get a shot done, whether you are able to see what's causing the effect or not.
Every film has had glaringly noticeable effects because of the lack of budget (ED- Exposed tubes and projected moon; ED2- Strings and claymation; AoD- Too much to mention). For a series as cartoonish as Evil Dead is, CG was more than likely going to be used at some point. Sam wanted a possessed doll? Stop motion takes too much time and money so go with CG! Get that shot done! Being subdued and constraint are not in the spirit of Evil Dead. If it became that then you would probably see a lot more backlash from the fans. "Loud and out there" was what made people fall in love with the series in the first place.
And I used outbreak as a "you know what I mean" kinda term. Ash caused it all because he's dumb and was under the influence (which makes me even angrier but whatever). His idiocy is going to cost the lives of countless people. I know he's a goofball and Raimi enjoys torturing him for being stupid, but to sacrifice my caring of his character to really go out of the way to balloon that aspect (which wasn't one that I was too crazy about in Evil Dead II or Army of Darkness) was a really bad call to me.
It was so insulting that now I'm actively rooting for him to die. I hope he gets his just desserts for being such an ass. I'm going to continue watching the show and while I hope to enjoy it, I am absolutely fine with lots of complaining from my end.
Here's the way I figured it and how it seemed to be described from all the interviews. Ash has fallen apart over the years. "The hero from the sky" is stuck with a crappy stockboy job, is still missing a hand, living in a trailer, and is aging. He's clearly lost touch and is falling apart. He is trying whatever he can to keep a grasp on his youth, but failing at it. I wouldn't doubt that for some selfish reason he kept a hold of that book in hopes that one day something does happen and he can once again feel relevant.
Him releasing the evil and causing people to die is no different than what he did with 3 little words in Army of Darkness (where he was even more of an ass about it there). It isn't until the end of of the episode where you start seeing Ash the Hero that was at the end of ED2 and AoD.
As for his comeuppance? Well if tradition follows then Ash will have some kind of downbeat ending happen to him.
EDIT: Also just because it grind my gears, I continue to be displeased with the "you don't understand" counter to criticism. I'd like to think I understand the series just fine and even if I didn't, the show shouldn't need to require understanding of its source material to appreciate it. The show should stand up on its own. I don't think it does. It infuriates me when people dismiss other people's feelings because "they don't get it".
The show does stand on its own. There really isn't much plot to follow here. Bad book is read from, bad things happen. It's not like Evil Dead has a deep lore to it. Also fans, including myself, have been on a rollercoaster ride waiting for Evil Dead 4 to happen for decades now. If the show wasn't a good representation of what Evil Dead was, then Raimi and Campbell would never hear the end of it. Other than the use of modern technology, the first episode is pure Evil Dead through and through, and the darkly fun nature of it is something a lot of people who aren't familiar to the series can enjoy.