I take it you mean PaintShop Pro Photo. I don't think there are any problems with it at all. Indeed it does a lot more with images in 16-bit than either of the Adobe products. It's also a great price.
Here's a list of features, with a comparison to PS Elements.
The only criticism that anybody could really level at it (at that price) is that there are far fewer tutorial resources for it on the internet, or in books and magazines, compared to the Adobe offerings, so you've put your finger on it when you say "Photoshop is everywhere". Many of the techniques of Photoshop CS transfer quite well to Elements.
(My own feeling is that Elements is actually sufficient for anybody other than a professional photo editor - I get some stick for that but it usually comes from people who have spent lots of money on full Photoshop and are not about to admit it was a mistake. By the same token, I'm sure many people are perfectly happy with PaintShopPro Photo. Just like the camera equipment itself, there's a lot of snobbery about programs - as well as about the Apple vs Windows argument.)
PSP does many tasks in a very similar way to Elements but I find (being involved in a camera club) that newcomers to photography, after they get their first camera, ask their friends about how to edit and their friends have possibly only ever heard of Photoshop (which has become almost a generic verb as well as a program name). So the newcomer looks for Photoshop - and then, when they realise it's very expensive, find Elements instead. But that could easily be PaintShopPro, notwithstanding the tutorial situation mentioned above.