Back in the Games Factory,or the second gen of Clickteam products, this was a common place feature. It is not actually an extra feature people are asking for, rather one that was effectively removed without much warning from "Higher" versions of the Click platform. Instead of having separate global events and behaviours, you had groups you could tick a box, and the events would be global. I don't remember there being any restrictions on this in terms of qualifiers, and I made several short games this way.
I don't really know why MMF has this limitation, but the way people "get around it" aside from using level editors seems to be mostly down to copying and pasting code, either from object to object in terms of behaviour or frame to frame.
The thing is, there's no reason why the old "Global Events" couldn't be restored. Essentially what you can view it as doing, is copy and pasting the same event groups again and again, for every frame, but automatically. It may even be possible just to mess with the pointers so all frame events are pointed to the same frame's code(within a certain group, anyway). If this works - there's no reason why this couldn't be done internally and automatically. There is nothing magical about clicking and dragging, it's all just calling internal functions - so it would take a very short amount of time to implement a function that emulated the 2nd Gen way of doing this. It may cause some issues that are already existent with global objects - but that's already going to happen with copy/pasting.
I can't see any reason why this couldn't be put in the next version and it would effectively fix this problem for most people and cut down on a lot of waste. I don't think it should be assumed this can't be done, again I don't think enough importance has been assigned to it because most of the people for whom this was an issue gave up long ago and moved on, but a lot of people still know MMF best and could be tempted back with a simple fix like this.
I'd ask people to at least not make excuses why this "shouldn't" be done or why it's not important - it is important to some people and would benefit many users of the software even if they haven't thought of it yet. Please also understand that if it's possible to make "global" code by manually copy/pasting it's possible to do this internally/automatically.