> I do not see the issue here, either.

Despite there not being an issue, there are many companies, including some very significant ones, that have restrictive rules about the use of GPL software just-in-case. Some flat out have a blanket “no GPL code at all” for the libraries and such that they use. I don't know if it still stands, but Android development at Google had a “no GPL in userspace” edict. If your service becomes big, you will get people asking you to change the licence so that they can use it.