This is a rare case of an accessibility feature often being someone's roadblock...

Eh, many people use computers but are not the ones who installed the operating system (e.g. work, school, library, etc.). I think it's likely more accessible to be able to enable the feature at any time, if needed. In my experience pressing shift five times generally only happens to me when playing games. I don't know how often it pops with normal web browsing, email, etc.