We can't know if we didn't ask the users, so your assumption is just one of many reasons.
Do you think that the low pay makes some reputable posters to leave the forum in the name of no freedom of speech and censoring?
I would say it's better to separate low pay and freedom of speech/censoring.
The forum only censor direct URL link, anyone who want to discuss about certain mixer, review, how it works are still fine. We can say the forum has no freedom of speech if talking about mixer will get punishment.
One thing I know is that as some people will go, some people alt accounts will come.
FTFY.