once everyone is doing it, it's not cool anymore
Why would that be? If everyone had a garden, would you dislike flowers? If most people around you were playing music, would you not enjoy dancing anymore? All the instruments available playing at the same time, or all the perfumes combined will quickly lead to saturation or even become hurtful, but with careful orchestration from capable/creative people you will get countless enjoyable moments.
As with anything else, the Internet experience needs a bit of guidance and restraint, but as a concept I find it nothing short of amazing.