I can see a few reasons for this. From a business perspective, teams usually scale depending on the revenue their LOBs (line of business) create for the company. In a crude way, dissect comics as one LOB and novels as another.
Given Tapas' foundation as a webcomics platform, there are 10x, maybe even 100x more readers for that LOB than there are for the novels section. Since the teams scale accordingly, it becomes more feasible for them to evaluate more comics for all those nice sections on the homepage.
Trending and popular are algorithmically-driven and don't utilize human effort, but almost everything else is through the editorial team's efforts. Team Novels on Tapas is much smaller, I'm guessing. You also have to admit that it's a lot easier to review comics for quality and consistency than it is for novels. Reading words is simply more effort.
Plus, it's the end of the financial year as well. They have to promote their premium content to juice out as much YoY growth as possible, for their investors and such.
About the community comics section, I think they simply ran out of the second round of suggestions, and are probably cycling through the comic collection because ad-revenue. Tapas is a business at the end of the day. And as a novel creator, as much as I would like them to feature my work, and the work I enjoy reading, that's simply the truth of it. 
