Because if I’m on my phone, the SDMB is too wide to read.
Yes, because a phone is not a great device for browsing the web. If you are going to make an app that tailors the message board experience for a phone you are going to have to compromise on some of the things that make it a good experience on a computer. Add to that the fact that Tapatalk is a generic message board reader designed to give a functional experience on a wide range of message boards and it is hardly surprising that something gets lost in the translation.
I think the main problems are it not loading pages correctly (maybe because of switching between 3G and wifi). Sometimes when you click on next page on page 1 nothing happens, then when you click again you go to page 3. It’s still a lot better than the browser, though.