Is it normal i dont understand the purpose of erotic cakes?

I dont understand the piont of erotic bakeries. I mean sure it must be funny seeing a frosted penis but aside from being immature and giggling at "Oh my god.. Boobies"! are they suppose to do anything? I mean are you suppose to get off from them? I have heard of dick cakes that are cream filled. That sounds kind of gross but anyways why do people do this? Also no I am not trying to discourage it. If you want to invite people to your home and have a penis party that is entirely your decision. I am just curious as to why people do it.