Could this be the reason , It's like 15-20mn to get at least 1 confirmation if I'am correct ?
Anyway the point is that we need some time to get transactions verified , could this actually prevent us from going to mainstream ?
No, IMO other things are preventing bitcoin from going mainstream. It doesn't really solve a big problem in most peoples lives. It wouldn't make life much easier for most American's purchases, and would probably just complicate things and introduce new risks. It has niche uses but for most people's everyday purchases I doubt it will ever go "mainstream."