Boards have increasingly enacted rules to cater to advertisers as they found out that simple word filters to stop “bad words” from being mentioned improve their advertisement revenue.

I remember Reddit when the purpose of the voting system was encouraging a laid-back approach by moderators on the logic that objectionable content would be downvoted, and hidden, so that those who did not wish to see it could ignore it, but that's long gone now, and moderators are highly zealous and on top of that one has the hivemind voting system to deal with.

Internet indeed became a pursuit of profit, rather than memes for fun.

And indeed 4chan never bowed to advertisers and consequently actually is not that profitable despite being one of the largest websites.

The culture on, say, IRC channels which do not rely on advertisement is very different from on websites that do and typically enforce various language filters.