Yes, I think that the assumption is that online will be cheaper. Another assumption might be that bike shops are for fancy bikes where super fit people who wear spandex go. I know that I kind of felt that way. Another assumption some people make is that they can figure things out on their own, with the help of online resources. Sometimes you need the experts. Whether it is medical, legal or bike shop.
I wish bike shops did more beginner stuff, like beginner rides. Sponsoring family fun rides could build up a reputation that bike shops are for everyone.