Blaming players for the metagame doesn't really make much sense when you're talking about a competition. If there's one style of play that clearly gives the best odds of success, it's obvious that people are going to use it more often than other styles. It's up to the game to encourage, and to make viable, a variety of different styles. Players can help it along, obviously, but it's unreasonable to expect people to handicap themselves in the name of manufacturing variety. The best way to encourage variety is to make it a competitive advantage.
Except that I'm never talking about Competition, and even I was that's a tiny, tiny fraction of the games played.
People who are playing "for fun" - which is basically everybody - aren't obliged to chose the optimum consensus load out. If they do it's because they want to win all the time, or they really care about ladder rank. That's a valid option, but then they don't have the right to complain that they are bored doing the same thing all the time.
What people often seem to want is for Relic to randomly change unit stats rather then explore alternate play styles of their own volition.
It is possible for the meta to change without patch, which I believe Relic have mentioned on Stream
We have had B4 be very popular, and Axis players have learned to adapt to it and change their loadouts accordingly and on-map artillery is now not so common
We have also, and in relation to that, had CAS and, to a much lesser extent, Advanced Warfare become more widely available and used. The meta around those has not yet settled down, but I think I am seeing much less CAS then we did a month ago.
Also we have people experimenting with Fear Propaganda and using those Commanders.