Unfortunately web browser, web apps and websockets can only use a few ports, so if you run a service that you later want to interoperate with a web app of some sort, you don't really have a choice. In a way, ports are already becoming obsolete for some applications.
Web browsers are actually quite flexible about what ports they can use. However some ISPs and “enterprise” networks will filter traffic on non-standard ports. That’s the real problem.
