Is there a reason why? Less funding? Web devs don’t make the pages Firefox friendly? Since the user base is smaller, they just don’t care?
I don’t think I’ve experienced this. Do you mean some pages not working in Firefox, but working in Chrome? That’s mainly because of parts of web standards that are ambiguous or undefined, and Firefox and Chrome have different behavior. Some web developers (read lazy web developers) don’t test in Firefox, so they write bad code. Both Firefox and Chrome follow the standards, so if web devs just stick to the standards, everything should work.