For what it's worth, the user score on Metacritc is notably higher than critic score - Sitting at an 8.8 at the time of this post.

So, unlike Other M, gamers and fans appear to like Prime 4 much more than the critics did - Which is a good sign for word of mouth and its legs. 

Well bellow my 85 prediction

Already dropped go 8.6 (and actually to 8.5 as I was typing). Yeah… I wouldn’t go off of MC user reviews. The game is going to get bombed, just like all games do. HLTB has a rating system which is far more accurate though it may take a few days for data to come in.

From what I can tell, MP4:Beyond falls comfortably into the category of a Skyward Sword/Mario Sunshine “black sheep” entry: you either love it or hate it. (I speak as somebody who loves Mario Sunshine and is very eager to do my first playthrough of Skyward Sword, so definitely not a bad thing!) Not anything like a Paper Mario SS/CS nor Metroid Other M.

On backloggd the game is sititng at 3.2 which imo is pretty bad. Pokemon Legends with all the hate scored 3.6 there

Granted the number of scores are pretty small so far (~300), so the low scores probably come from people who played and dropped

so I believe the numbers will go up, but will end around Pokémon

Dread scored 4.2 with 21k reviews

I really like Sunshine. I don't like Skyward Sword much, but more because I don't enjoy the control schema and because the game looks too much "more of the same" compared to its immediate predecessors, with a (in my opinion) less interesting world and story. The dungeon design is awesome, so if you play for the puzzles you will love it 

MP1 –> 4.4 out of 5.0,

MP2:Echoes – > 4.0 out of 5.0,

MP3:Corruption –> 3.8 out of 5.0,

MP4:Beyond –> 3.2 out of 5.0.

But as you said, Icaro, the score should go up with time. Hitting a 3.6-3.9 would def fit the “blacksheep” label, and would also emphasize that this game really isn’t the steep drop in quality which MC may suggest it as being. It’s clearly no Metroid Prime 1, but it’s also no Metroid: Other M; rather, it’s a solid entry which remains to stand toe-to-toe with other titles in this prestigious series.

…Also, side note: Kirby Air Riders is the highest rated NS2 exclusive according to Backloggd, sitting at a clean 4.4. That places it above Mario Odyssey and tied with BotW… that’s crazy lol. I absolutely love Kirby Air Riders, so you won’t hear me complaining about this!

is this guy just a hater? or does he have a point?

He praises the graphics. Best on the Switch 2 so far.

Complains about the side characters, cringe escort missions, and dialog writing.
Says they are so bad (the writing, that he would turn off sound, when they happend, if he was forced to rewatch them) (ei. a failed escort mission).
He died about 3 times (2 to puzzles he misunderstood, and once, to a fight). He hated replaying parts, that led to more cutscenes already watched.
Says its clear they had planned out samus's voice, and cut it and her dialog, because the npcs react like she talked to them in lines.
Complains that your forced to spend so much time on the bike, and you can't pick your own music unless you spend 30$ on a Amiibo for it (calls it scummy / greedy).

He beat the game in roughly 8 hours.
Says you can 100% it in about 10.

Says it lacks the metroid "feel", and gave it overall a 6 out of 10 score.
This is from a huge metroid fan... who went back and replayed all the old games, before taking on this newest one.

Also says it's weird the story line, picks up directly after the last game..... which was from like 18years ago (like it expects players know what happend, and just goes right on, without any further explainations).

He didn't like the story very much either.
  
possibly the weakest metroid game in the series.

DreamcastGuy is infamous for being bait. Ignore him.