I've always kept reading materials in the loo. Heck, I keep reading material practically everywhere, so yeah, there's usually books and always magazines and catalogues in the bathroom.
I'd only find it gross if it was close enough to the loo to get dirty, but I've always kept it in a rack or on a shelf. When I smoked, I used to read and smoke in the loo (not while using the toilet) because Mr. A. has athsma and it was easier to isolate the smoke that way. I lived in a 5 story walkup, and I wasn't about to go downstairs every time I wanted a smoke (and I wasn't ready to give up smoking at that point). I got a lot of reading done in the loo when I used to smoke in there. Gross to some, maybe. I think you just have to realise that many people are going to have different "gross out" points than others. Some of it is cultural, some of it is familial, some of it is individual.
For years I used to get grossed out by the thought of re-using my bath towel without washing it. I had no clue people did until I lived outside my parents' home for the first time. I eventually adopted the practice of towel re-use. Another example is not using shampoo on my hair. I never dreamt I'd ever be washing my scalp and hair with (certain types of) conditioner alone. In fact, when I first heard of it, it sort of grossed me out. But now, about a year on from trying it out, I only get grossed out when I actually use shampoo and it messes up my scalp.
I find different tolerances in people interesting.
