I think one of the problems with pinning down "minimal" (note how it lost the "-ism" about the time it lost any sort of specificity; "minimal" is now, for many people, a noun) is a divergence in strategies. On the one hand you have the "micro" tendency, the move towards small, itty-bitty sounds, ticks and clicks and pops and crystalline pings, or even just a stripped-back 808-inspired kit; this end of minimal is generally a-melodic, at times even without any discernable bass lines, and leads its critics to charge it with being boring, sexless, etc.
On the other side, you have music that engages with minimalISM as a strategy -- generally with an extreme focus on repetition. The irony is that much music that's genuinely minimalist in strategy is the furthest thing from what gets classed as Minimal -- Moodymann, Theo Parrish, that shit is seriously minimalist in form and intent. Even going back to the original Chicago house & acid house, that stuff was properly minimalist as well. Going back to Âme, their recent contribution to the Berghain ballet comp was way influenced by Gottsching and Steve Reich. Âme aren't really "minimal" in the contemporary sense, but they're certainly influenced by '60s and '70s Minimalism. (Of course, this brings up the problem that classical Minimalism was always a misnomer itself!)
Anyway, as a genre, the term "minimal" is by and large divorced from the word's underlying meanings these days; it's become a kind of free-floating signifier used most emphatically by its supporters (seemingly, a lot of 18-year-old Italians, these days) and its detractors (Detroit techno fans). Obviously I'm generalizing, but I hope that makes some sense...