It seems that in every game site, in every comment section/forum there's people saying that this game is good or bad depending if they liked the game or not.

I hate many above average games, and i love many average games.

Just because you like a game, that doesn't make the game good and vice versa. How isn't this clear for most gamers?

Even" professional" reviewers make this mistake all the time.

Thoughts please.

"Why can't people diferentiate between their personal taste and quality when it comes to anything?"

Fixed

Was trying to make it only a gamer problem, but yeah you're right.

I think you are trying to make something that is subjective into something objective.  The quality of a game is measured by your opinion of it.  That is the standard by which it is judged.  As such, the quality of a game can really only be assessed subjectively.

I think it's simply that many people do not know how to present their opinions in an accurate, mature, and less combative manner. When presenting an opinion, it is important to reinforce its subjectivity through your sentence structure, such as "I did not like the game because I struggled with the camera angles and controls", because using the pronoun "I", owning up to why you couldn't enjoy the game, and offering more specific examples will usually make other people accept your opinion, even if they don't agree with it.

However, the more usual expression of opinions on the internet is usually, "This game sucks, the gameplay was terrible," which, even though conveys a similar experience to the opinion above, is attributing it to the game instead of owning up to your own subjectivity. Often people will add an "In my opinion" and then proceed to say, "The game sucks", which doesn't really change the fact that you're expressing the opinion in a poor manner.

Welcome to the internet.

Every person has prefference. A game is only good is it can be enjoyed. If you are going to base your purchase on someone else's opinion it helps to know their prefferences. I like Nintendo games, I like adventure. So if you do too, you can use my opinion. I don't like Sony games, I don't like turn-based rpgs or racing. So i tell you killzone, knack and gran torismo are bad.. don't listen to me.


I wish gamers and reviewers wore badges

It's common problem. Emotions against thinking.

Whether it's your preferred taste or not, doesn't mean that a game isn't a bad game. If you ask me, there's so much bias over franchise or developer/publisher that too many games that aren't deserving of praise still gets it. God of War is good, no denying that, but a better game like Dante's Inferno gets slammed because not only is it a God of War ripoff, but because of the publisher, and the game is far better than any of the God of War titles.

Garbage like Ni No Kuni receives massive amounts of praise for no other reason than its pretty graphics and the fact that it's a collaboration effort between Level 5 and Studio Ghibli. The storyline isn't very good, even if this game was released in the silver age of RPGs. Magic that's practically useless because it costs way too much and normal attack combo will take off more. The game is pretty much a button masher where you're constantly hitting x the entire time during combat, rarely defending or doing all out defense unless it's on a boss.

Pokemon at its core has a deep layer of strategy, but what about the main game. That 20 hour storyline where you're slogging through against Pokemon that you'll OHKO throughout the game. Then in order to get to the layer of depth where the game is actually good, if you want to do well, you're going to put in a minimum of 5-10 hours getting a good Pokemon team decent IVs, then the time it takes to level those Pokemon to 50 and get the skills you want them to have. Every single time a new Pokemon releases, it's common that even fans will admit the main game is boring and repetitive, but the game gets a free pass because the game has an underlying amount of depth that most people will rarely experience because of the amount of time you have to put into it? 

Too many games get overlooked because regardless of the system, you have a group of fans praising one game that doesn't deserve it, usually when it's exclusive. Additionally, Nintendo fans overlook a lot of quality games that are on Nintendo consoles simply because they're not developed or published by Nintendo, although being exclusive helps.

Finally there's the fact that people haven't played all these games. Unfortunately there's nothing that can be done about that, but if people actually tried out different games than sticking with just Nintendo games or play the highly rated niche titles also instead of only the over hyped games then people might actually start playing some games that are better than those they're accustomed to.

Lack of perspective.