the thing about learning to build these yourself is that it teaches you so much about acoustics, signal processing, and the very basic principles of synthesis that is very hard to learn any other way , especially when you're having loadsa fun twiddling knobs on FM7, or your trusty VA or whatever. There's nothing like getting your hands dirty
Ive just recently got into Supercollider , and apart from learning loads , the power and flexibility is just awesome. Sure, if you want quick results which sound like everything else then it's pretty pointless , but there really are endless things you can do with it which is either impossible or very hard in any commercial synth out there
That sort of stuff isnt for everyone i would have to agree, but there is definitely a point to it all!! The next two years of my degree is pretty much centred around this stuff , so hopefully i'l have something to rival techmouse's legendary square wave generator by the time ive finsihed ;)