Dividing up sound synthesis into its different modules (VCOs, VCFs, VCAs, LFOs, etc) makes perfect sense coming at the problem from a programming point of view. It turns sound synthesis in a Lego toolkit and there's no end to what you can create by combining all these in novel ways.
There's a lot of aesthetic enjoyment to it too. Putting together an octopus jumble of patch cords, seemingly random and impossible to keep track of to an outsider, just looks really badass :) Even better that it's actually a deliberately constructed mess, all in service of generating a sound you've never heard before, and when the cables are all disconnected, will never hear again.
The overlap between the tech and music worlds in the modular scene is great as well and it's very cool being able to talk to people who can get both technical about music and artistic about technology. For us, the modular synthesizer just makes sense.