To address the OP's point, I don't see how Voyager was more popular either. DS9 had a much better cast that was much more thoroughly explored and well-used and made wonderful use of continuity while Voyager's cast was often underused or used poorly and often dropped the ball on chances to have some connectivity. But despite that? I like Voyager! I don't LOVE it, but I enjoy it. As for why:
The biggest reason I suppose would be characters. Tuvok, The Doctor, Tom, and Seven really made it worth it, and despite its flaws Voyager has what I consider to be some of the best episodes of the entire franchise. I also always liked the design of the Intrepid and the look of the interiors. When they did episodes that only Voyager could do, they usually knocked it right out of the park. I have my beefs, but only because I think it could've been that much better.
The biggest reason I suppose would be characters. Tuvok, The Doctor, Tom, and Seven really made it worth it, and despite its flaws Voyager has what I consider to be some of the best episodes of the entire franchise. I also always liked the design of the Intrepid and the look of the interiors. When they did episodes that only Voyager could do, they usually knocked it right out of the park. I have my beefs, but only because I think it could've been that much better.