I agree with @keii4ii and @carloswebcomic : the front page is supposed to be intuitive for both readers and creators. Not everything on Tapastic is built to net you more readers - you have to do some of the work yourself. For the most part, the front page is the first thing that readers see, and even though most of the comics on the front page are there all the time, they're there because they're high quality comics and they do a better job at representing the site and what awesome stuff you can find here. If I went to the front page and saw comics that were either poor quality or just one-time postings (which a hell of a lot of comics end up being) it wouldn't be a very good first impression of the website. It's not built to just get you new readers - it's built to draw in more readers to the site in general, and seeing as how Tapas is a business, it's understandable they'd want the first impression to be good.
The only point I can agree on is that the Popular/Trending sections really are the same every single day. I can probably list 10 comics off the top of my head that are there either every day, or pretty damn well near it (if not every day then at least 3-4 times a week). While we have to give credit where credit is due - yes, these comics are popular for a reason and a lot of people come to Tapastic to read them - it gets very bland and very predictable when you know you're going to see the same comics in that section, sometimes in the same order, every time you sign in. I don't know what could be done about the algorithm at the moment though; I know Tapastic has a lot more things on their plate ATM so the algorithm that the Popular/Trending sections are based off of might not be a priority (at least not right now).