Speaking specifically to your anecdote, most people do not finish most games they play. Even on enthusiast communities like this one, the completion rate for games is shockingly low.I did some math now and removed all scores below 5 from average(supposing it's an arithmetic average) to see the effect of review bomb and the result I got was ~85,9. Not saying that MC user score is a representation of the whole market(because it isn't). My point is that people who didn't like the game(I am not included despite my amount of criticism) needs to see some changes to be interested in the next entry. That's why I believe they will drink in the old formula fountain and merge with the great achievements that Breath of the Wild brought.
Some personal anecdote. I live in Brazil where videogame console are very expensive even though the power of Switch and BOTW word of mouth made a lot of people from my job to buy them. As I'm an avid Zelda fan and my coworkers know about that, a lot of them talked to me about their experience with BOTW(usually their first Zelda) and a good amount of them dropped the game without finishing.
I alway wondered, for example, if the people that disliked Twilight Princess(hyped launch game of a hyped console) contributed for the weak sales of Skyward Sword(though there's are other reasons already discussed in this one).
With that said, there is a second point to consider, which is selection bias- Metacritic is a recent phenomenon. It didn't exist back in the N64 days, and its prominence in the Gamecube days was limited. The only people who would bother to try and find an old game to leave a user review or score on it are people who enjoyed it, which leads to self selection bias and score inflation.
I agree with your larger point- BotW is amazing, it is not perfect, and it could stand to be improved in several ways. No arguments there. However, I disagree with the examples you have used to illustrate your point so far.