There are people called producers, and yeah they'll suggest/force things on games even if the dev doesn't really want to do it. Ico doesn't tell you anything about how to play it, and SotC only really informs you on how to do a few things like the grip mechanic. The amount of tutorialization in The Last Guardian is much higher than in prior two games, button prompts and narration hints especially, and I can't be convinced that these weren't forced onto the game by higher ups at Sony.
Producers aren't executives and also don't work in tutorials: they only manage the teams: making sure the dev team reach milestones on time, managing resources or budgets, solving issues that may appear in the tasks, hosting meetings. Tutorials are designed by game, UX/UI and maybe even narrative designers, and their boss the creative director (in this case Ueda) may ask them to take certain approach.
For actions that are exactly like in a ton of previous games, or for games where you only have a few possible actions to do, tutorials aren't needed. This was the case of games made time ago. In the past games also were developed in a few months, so they also didn't have time to playtest them properly so they shipped the games without testing them a lot and without detecting if too much people got stuck or frustrated in specific places or they didn't understood stuff. These are the reasons of why old games had a broken difficulty and didn't have tutorials.
Over time development lengths expanded for bigger ganes, game designers started to have access to longer playtests and in-game metrics that stored statistics of how people played and where people gets stuck or frustrated, so they started to fine tune the learning and difficulty curves according to most players needed. They (or we, I also have been working on that during years) also iterated with different types of tutorials or indicators when things were detected that most people didn't get them properly.
Specially in games more targeted to a more casual and mainstream audience or games that had very different/new/weird mechanics as it was the case of Last Guardian, game where that was specially difficult because unlike in the other games here you don't get instant feedback of your action: you have to wait for the ratbird to see if you did or didn't the proper action. And sometimes maybe you did the propear action but the ratbird didn't react as supposed so sometimes you had to try different times, with different timing or having the ratbird at certain distance.
When gameplay doesn't react as the player expects or isn't intuitive enough and doesn't see a clear reaction to their actions, the player thinks it's the game's fault and that the gameplay sucks. So in these cases gameplay must be tweaked to make it more intuitive and with clearer hints/tutorials or visual/audio/rumble feedback, specially rewarding the player at the moment just after doing things well.
In terms of gameplay and mechanics Ico and SotC were pretty much standard outside having the huge enemies/moving levels in SotC so basically didn't need tutorialization/too obvious hints, but in TLG the things I pointed above were specially problematic, and I assume the final game had a gazillion iterations, improvents and tweaks over the original concept and even after that was shipped with a gameplay that many people didn't like.