So, why aren't we allowed to break meta before the pros do?

Most people on here seem to get instantly enraged at any meta-breaking picks, and to me that doesn't make any sense. The meta stops being a metagame at that point and starts being "you're only allowed to do something if pros do it". For example, Lulu mid was awesome, but when you tried to do it before it became a pro thing, people flipped out on you and threw games over it. At some point, some pro does it, then all the sudden it's a thing, and it's ok, despite the champion being exactly the same as before they did it.

Wouldn't it make more sense to just play the game and see if the guy had a good reason to pick whatever abnormal thing he did? I'm pretty convinced that the majority of the time that breaking meta fails, it's because the team implodes, not because it actually performed poorly. For some reason people will often sit there and not say anything about the pick(even in team builder) until the game is already started, then they try as hard as they can to blame everything on you. I've seen people go so far as to say they're getting camped by the jungler top because bot didn't have a metagame adc. What gives?