[koz_]

By that logic one shouldn't ever criticise let's say, Google (a separate entity), because in theory one could get a job there, work their way up to be CEO and then change how the company works. In fact, why ever criticise anything or express any opinion when instead you could be 'doing something about it'?

I think it's okay for people to express their opinion on the internet, and it's not a moral failing that they are doing that instead of, as you suggest elsewhere, running for office, getting elected, writing a bill and finding allies.