Controversy = attention = ratings boosts = higher pricing for advertising = more cash for Bill.
A formula that every well-known conservative talking head practically lived/lives on and by, ie- every single talking head at FOX, Limbaugh, conservative AM talk radio etc. Don't see why Maher is any different. In the end, all trails lead to the double bottomed line.
That being said, it's much easier for the right to create controversies because they're mostly, if not all of it based on lies and misinformation. Much harder for the left to create controversy based on facts and truths, although Trump really did make things much easier for the left just from being who he is.
It seems that Maher is stuck in the middle of it all, playing both sides in order to, among other reasons, keep his ratings (income) from suffering due to the way the current political winds are blowing.
Personally, I've never considered Maher's dry wit as being comedic, he seems to be more of a third rate D list version of guys like Jon Stewart and Stephen Colbert.