Well, for some people a literal crutch is temporary, some people need it for life. There’s not a lot of people who need a literal crutch for life, since it seems like they either recover or get a wheelchair. Either way, this metaphor is getting in the way of the actual point. You use a crutch to help you do what others can do normally. If your stutter is something that can be cured, then obviously using a crutch when you don’t need to anymore is detrimental at worst, lazy at best. Going back to the literal crutch analogy, if you tear an ACL, you’re going to have to work out that ACL one way or another, and using a crutch will prevent you from working out that ACL. If you had polio as a kid, then your legs are fucked anyway and you’ll need to use a crutch for life. So to answer your original question, crutches aren’t bad. Using them when you don’t need to is. And most people who tell you crutches in general are bad have no clue what they’re talking about.