Neat thread, if for nothing else, maybe people venting here will help reduce pointless clutter in release threads..
First up, my general attitude towards imaginary rights is, in a word, abolition. If you have a piece of data, practically any data, you should be free to give that to anyone (or everyone) at will. Some exceptions for slander issues might be applied; military secrets should be a separate category still; "civilian NDAs" would be written as contracts with payment bound to "continued silence".
Pay a coder for time spent, an artist for an agreed contract, and have the chips fall where they may. Sounds horrible? Well, at the moment people are praying to hit an algorithm in a suitable way to go viral and sell a ton of ads for google... It would change things, but not by a whole lot. Just less of Disney and more of "crowd funding".
That out of the way, I'll answer those questions.
Why do you like/dislike the idea of authors monetizing their work?
Are there legal issues? Moral issues?
I can't really say I like or dislike monetization per se; there's better and worse forms, but the concept of "someone trying to sell me something" is pretty neutral in itself. I'm free not to buy, and I usually don't.
Legal issues.. well. That's a matter of local law.
Moral? I think my abolitionism covers my morals.. information should be free. It's not wrong to keep someone out of your server, but it's wrong to install a rootkit on theirs.
What positive/negative effect could monetization have on the community and the “art” itself?
That's a wide question; "could" be anything. What it practically looks like from the outside, a couple stupidly hard-working individuals can make a decent income on a patreon, some more will make a pittance. Unless you're working 80 hours a week on your craft, don't expect much. Heck, even if you are, the odds are against you.
Does it change the art? Ehh. Some will improve from working harder to earn more, some will burn out trying to churn out stuff to sell. The audience starts influencing some more, people will start trying to please everyone and lose their own interest. All kinds of things happen.
Are there types of monetization that you prefer, If any? Why?
We're on a porn site, soo.. anonymous. Preferably more anonymous than bitcoin. I can't think of one, though. Which kinda leaves me in a pickle.
Other than that, a donation system is likely the best for this type of community. The stuff can't really be "sold" as it usually relies heavily on other copyrighted stuff anyway. And I think adding google ads might be a bit of a turn-off...

Hard paywalls is a no from me; I'm not signing up to a shady site with my direct payment info. "Whaddya mean shady?" Well, you're peddling porn, someone else's porn at that. If that doesn't scream "shady", I might have a bridge to sell..
Is there a way to find some compromise? Approaches that would work for both authors and viewers?
That's an artificial split for the most part; the creators are also the viewers, and most don't seem to be looking to make a career out of this. For the few that place things behind paywalls, I'm sure they've looked at a lot of compromise options, and found them all wanting - a paywall is not exactly an easy sell, so the audience will be limited, they have to view the compromises as pretty poor.
Why is this issue controversial and why it evokes such a strong emotion in us?
The cynical response; Disney is great at one thing, propaganda. They've made everyone think that whatever they wrote on a piece of paper once is theirs to keep forever and ever. Because Disney's bottom line demands it.
A little less cynical; it's just a complicated mess all around. I've held my abolitionist stance for quite a few years by now, but it took quite a bit of reading and thinking and arguing to end up at. The tricky part was to let go of the idea that creatives "deserve" their compensation. In a way still, yes they do; if you're agreeing to have someone spend time to create something for you, you're obligated to hold your end of the deal.
But the creation of a digital copy of a set of data; that's no longer the artist working, that's a mundane digital copy-paste. If you can't gather a lot of donations, or auction some work for piles at once, you might not get rich by being an artist. But it's not like 99% of even-somewhat-good artists manage to make a living from their art.
From what I've seen, that is the part that ruffles the most feathers. People have wildly differing ideas of what is "right". It manifests in different types of arguments, but the core differences are usually somewhere along the line of "deserving" something. Add in some interesting personalities (artists are known for their stability, right?

) and the discussions get a little wild.
Do you want to understand where the opposite position is coming from?
Me? As my final position is pretty much "You do you, boo. Good luck.", I don't think there's a real opposite.
How can we fix this mess?
Trust me, we can't. People will keep launching paywalled projects, and others will keep complaining about them. Even if we managed to convince everyone to chill today, some more will get born tomorrow.
Even if we were past money in a "luxury communist space utopia" or whatever, I'm sure people would still be launching paywalled projects where the currency would be something .. raunchier.