Toot is a sophomoric word for passing flatulence in the US. So hearing “to toot” summons the mental connection of farting which any marketing person on here will probably tell you people don’t want to be associated with their product.
Indeed. This isn't a question of maturity as some rather bizarre comments in that issue claim. The word is just phonetically and pragmatically asinine. Pick a word that isn't associated with comical bodily noises like "choochoo". Would anyone join a service where you "choochoo" at people? It sounds stupid and infantile. "Tweet" is bad enough. "Toot" goes further.