Professional media critics -- particularly movie critics -- tend to have education related to media study. Literary critics tend to have literature degrees (or at least humanities degrees), except in the case of independent bloggers/streamers/tubers/whatever. Even a lot of them do. A huge number of media critics also have education or experience in acting or media production.
Compare the gaming journalism industry. I know literally zero gaming journalists with a literature degree, and only one with a humanities degree. I know of only one with any formal literary analysis education (myself) and I never finished my degree. No journalists that I know of are former pro gamers or have any significant gaming history. Most have no industry experience; gaming journalism tends to be a stepping stone towards working in the industry for many. Generally, once you've got a job in the gaming industry, you tend to get other jobs in the industry rather than working for a media outlet. This doesn't mean that gaming journalists aren't educated, but most have some other education that doesn't give gaming insights such as web/graphics design, computer science, and so on.
The average quality of gaming journalism is really poor. The writing quality is pretty bad even in print publications, and online publications tend to be terrible. Most of this is due to the lack of writing education among gaming writers. Most of our language comes from the games we play and the books we read. I had a discussion that went far longer than it should have with another gaming journalist about whether we should use "they" as a gender neutral pronoun. For writing professionals, we kind of suck.
We're even bad as gamers, too. I really hate reviews that emphasize aesthetics or story over gameplay, especially when that same reviewer does the same thing continuously. We're game journalists. Not art critics, film critics or literature critics. Yes, many things can sell a game, but when a journalist bashes a good quality game (objectively speaking, not based on my opinion) and says "I couldn't get into it" because the game was visually unappealing or because he didn't like the story, it makes me really angry. Yes, those things can hurt the experience, but the point is to review the game and not the story or the visuals.
I also hate when reviewers inject excessive personal bias. Game reviews are biased. There's no way around that, but most reviewers are really bad at separating their own personal preference from what makes a good game. They're also really bad at identifying what an average gamer might like. Reviewers tend to almost exclusively use "I liked it because X" and not "It's a good game because X."
An example of how to not do this is when I reviewed Path of Exile. Let me go right up and say that game is not my type of game. I just really couldn't get into it, and I would never play it without friends (I don't play it now). It's not a bad game, but it's definitely designed for a gamer that isn't me. I pointed out my hangups with the game, talked about the strengths of the game and said that if those hangups aren't a problem for you, you'll probably like Path of Exile. I did the same thing regarding LoL too, actually.
What I hate the most about
The biggest reason why gaming journalism is like this (all of the above) is because honestly, we're not paid enough to be professional. Let's say you get paid 100$ to do a review of a game. It takes you 15 hours to beat the game, 3-4 hours to write the article and you didn't get the game for free. Now I will give you the big shocker, too -- we're paid even less. Most gaming journalists don't even get paid, though it is possible we will get a review copy of the game. Streamers get paid less per hour on the average, but the flip side is that they can work more than we can, and popular streamers make more than us. How can you expect gaming journalists to be actual professionals when we don't even get paid minimum wage? Most gaming journalists cut corners in some way; not actually playing the game enough to do a full review, for instance.
Is it any wonder then that biased reviews occur? All it takes for us to like the developer is for us to get a review copy. We don't even rate bribes. We're so poor that getting paid and getting to play games for free (ish) is enough.
I'm not sure what the answer is. You can't pay gaming journalists with money that isn't there. Someone has to foot the bill, and budgets across the gaming blogosphere are pretty lean. There's a 1% that makes a lot (people like Yahtzee, TotalBiscuit, etc) and a lot of people that make basically nothing. Even the well-off guys aren't that well-off. It's really telling that gaming celebrities make six figures or less when the industry is bigger than the movie industry.
That's a tangent though. God the gaming industry is messed up.