Well, someone I've always admired is Morag Lewis, AKA Sunkitten. She's been making stuff for years, not just on Tapas, but in print too, far pre-dating Tapas even existing, and has always been a huge supporter of UK manga artists. She doesn't really mind that her audience isn't huge, because she's happy in her day job as a molecular biologist (awesome).
Her comics and novels are seriously pretty enjoyable reads too. I actually cosplayed one of her characters once (Kite from Looking for the Sun at a con a long time ago that she was also attending) because I've always thought she's a really underrated creator.
When I look at her output, how much content she's made, and how she doesn't really care about popularity, I really feel humbled. It really takes just such a cool person to do that.