May I also add, this request seems to appear almost every other week (seriously, try search) and the same arguments given.
For the record, I'm completely against the coding part for the reason given by Miu3. This is an extremely good event-driven system that can be enhanced using the SDK, and that's how I'd like it to continue.
Also, in the long run, I am pretty sure that allow coding will let the event system go down, since at the ending, people will say "don't use directly the event system, use the coding part instead", and so, the event system will take the risk of not be improved anymore
(I know that some GM user says that you shouldn't use the D&D system, and do entirely in GML, I don't want that to happen in C2, I payed for an engine that always improve, without Us having to do filthy workarounds, because if there is a problem with the event system, it has to be solved at some point, not being left ignored, also, C2 don't do Code before export)