You're backing into the truth despite bad data. Reddit's published numbers are between a factor of 10 and a factor of 100 off of what any other measurer uses. There are blog posts early on where the team slags on Alexa and the like because they aren't measuring "true" metrics. Those same rankers also point out the major terms that bring people to Reddit - and it's all porn. All of it. All porn. But reddit's numbers and reddit's monetization aren't inextricably linked because they bill you based on what they say the numbers are (and they rip you off HARD). However, they can't count when you have adblock on either, so yeah - it makes sense for them to serve the communities too stupid to run adblock. For the longest time, the only thing that gave you karma was outbound links. That's not by accident. Outbound links increase Reddit's siterank, internal content does not. Things flipped when 9gag and the like started raiding Reddit content; now you get points for pretty much everything you do... but it's still all about "what can we do to inflate the metrics." And yes. Nothing in /r/depthhub will do that. Imgur started out as a Reddit plugin. It now has higher profit and higher numbers. That's when Reddit decided to do their own image hosting - when they were basically an Imgur optimization engine. It's a shitshow from stem to stern.
I sorta think the VCs told Imgur to quietly add comments and become a community separate from Reddit because reddit is legit toxic. There's a reason they dont' get more money. Toxicity doesn't sell.