[sethrin]

I just did a quick GitHub search, strcat seems to have been used about 5 million times across all repositories, as compared to (e.g.) memcpy at about 80 million. Clearly somebody is using it. I would hate to try to get a measure of how often it's used in other languages; it's not the sort of thing anyone would think twice about. I believe you have made an inductive error based on your own sample and that the original premise is entirely correct.