You say there's only so many translators. Yet, almost every time something is released there's thousands of people complaining that the translation is wrong. So who are these people?

You might not call them "translators" but they can speak both languages. There's lots of these people and I'm sure that if the work was well paid then many of them would jump at the opportunity. The issue is that it's not well paid. Those who want to do translation work and not live paycheck to paycheck often have different jobs and translate work as a hobby, e.g. many Anime and Manga translators.