Gamers are the worst thing to happen to gaming.
This quote is just true, in any given scenario.
Yo me gamer just means someone who plays a game. Games need to be played, so gamers are needed. Is there another definition of gamer you are using? If so, what is the definition you used?
Contextually, it probably refers to the gamergate thing. See the
"gamers are over" article on Gamasutra (which is a site for game industry developers), for an example of the context, and as one that generated a lot of offense.
It's similar to noticing that
some Star Wars fans are toxic, then just saying "fuck Star Wars fans" then when a lot of Star Wars fans get offended, you say "I only mean the 'toxic' Star Wars fans, not all fans - why are you butthurt? Only a toxic fan would get offended that I said 'fuck Star Wars fans' ". Similarly, a bunch decided to define "gamer" as "toxic players" then when they started going "fuck gamers" they got surprised that a broad swathe of players got offended. For a while, the implication was that calling yourself a "Gamer" was like being an armband-wearing Nazi or something.
It really is part of a corporate trend where they have a die-hard core of loyal fans, and they somehow convince themselves that the
core fans are the problem behind why their thing isn't more widely popular, so they then dump a shit on the fans and try and appeal to non-fans, and then get surprised when more often than not, the thing implodes. Really, the game industry just wants to exploit the masses so they decided that hardcore gamers were holding back sales, and took a dump on everyone who's a long-term video game nerd. The industry really hopes that games will become like movies, i.e. just about everyone's played the latest blockbuster game the same as just about everyone has seen Pulp Fiction or something. but for that to happen they feel they need to shed their dedicated fanbase and make stuff that has "everyman" appeal. What that means however is games that only appeal to everyone but in the shallowest of senses - no deaths, all quick-time events, no need to learn skills.
So from the corporate point of view, gamers are a problem because it's because of gamers that we ended up with all these in-depth genres popping up rather than all being good little mindless consumers where every family's bought the latest console and everyone is happy playing all the casual games they shill out.