Good games can be made in anything that accepts directions and doesn't lose performance in doing so. Unlike MMF though, Game Maker doesn't exactly hold up to it's name when it claims to make great games without writing a line of code. Multimedia Fusion does. Even expressions themselves, are capable of being piled up through a point and click interface.
You could write games in malbolge if you so desired. Its more the idea that MMF/TGF differentiate from the norm programming languages by trading the raw power and configurability for ease of use and expedient creation. Most C++ projects can be completed in TGF in 1/100 the time development. I could create a game in one hour in TGF that might take a C++ programmer most of his spare time during a week.
However, with that ease of use comes extreme limitations. The architecture is artificially limited at every turn; only 3 (26) variables per object? Only 32 boolean flags? No built in arrays? No if/or/else statements, lol? And on top of that, if you want to create professional grade projects, things that work mathematically properly, you need to throw out all the "easy" options that MMF throws at you, such as built-in movements, built in music/sound players, built in "level frame" system, etc.
Its the sheer brilliance of using a grid-based programming architecture that makes kliking so worthwhile. The whole idea of coding being a matrix of conditions and events rather then poorly parsed english language, is what makes everything go 100x as fast as C or Java. If conventional programming were writing, this would be painting.
Game maker, on the other hand, basically is something along the same lines, but not as brazenly geared towards being expedient. The tradeoff doesn't work too hot when you consider that MMF2 is easily as powerful as game maker, anyway, so all you're getting is an environment thats more familiar to programmers who learned in conventional languages, even when its less efficient.
I think you highly underestimate the power of MMF, if you can call it "extremely limited". No, it can't compare to C++ or anything, but MMF alone beats a lot of low to medium level programing languages out there.
wouldnt each and every event essentially be an if statement? as the fastloops essentially are a for loop?
where are the do/do for/while loops? where are the previously stated built in arrays? why arent there double, float, long, short, unsigned, etc. variables? and on and on and on.(or maybe this is all adressed in tgf2 and mmf1.5/mmf2?)
all in all, although clickteams mmf is powerful, it is essentially also very limited. theres nothing in comparison to raw programming power.
as for beating low level to medium programming languages Brandon, i think you are completely wrong. although its harder to use and learn, Assembly is very capable of making amazing games. ive seen amazing raycasting, vector, 2d platform games, etc. made in assembly. and although Basic is considered a higher level language ive seen pretty good 3d rendering done. mmf may beat out most in ease of use and understanding, but i wouldnt say it beats them in terms of functionality. and i dont think it ever will unless they include a way to include your own code as well as event coding.