Is not about morality at all- It has to do with the way the cyclists there are brought up to the sport: The majority of them come from farming/agriculture families with no funds to support their sons sporting career-so that means they have to train very early in the morning-4:30 to 7:00 AM, then carry on to either work on the farm or attend school, and afterwards "earn a living/helping their parents with labor". meanwhile, the kids may attempt to compete here & there on the local races "just to get an sponsor's attention" so they can at least "buy proper equipment"-best case-the sponsor might take care of the expenses of racing-but no salary at all.
you see- those kids don't even have money to even buy a decent bicycle and an uniform to begin with- let alone buying dope or having the "knowledge of doping" at that stage.
The approach & introduction to doping in Colombia happens when those few very talented riders already in the Professional ranks get enough attention from the "usual suspects" (Raul Mesa, Botero, all the "paisa mafia", Cycling Federation along with some "dirty Old school riders" with European experience & nonetheless the infamous Oscar "babyface" Sevilla) running the sport there, start to "emphasize" the need of doping if they're pursuing a career in Europe, so they need to start getting accustomed to it. I'm sure those guys I mentioned have the "system" and the "know how" and most of all-the "means" to get the dope for the riders, in exchange for a commission/percentage in their contracts, as soon as the transition is made. Remember: these kids are coming from poverty and they're convinced by those crooks to do it as "the only path" to achieve results/make money...
The big difference here is that Colombian riders are brought up "clean" and the majority stay "clean" because there is no real "doping culture" in their environment in order to "sustain/embrace it at all to begin with, whereas the European & American counterparts already have both available in the very early stages-"the cultural acceptance & the money" to execute it.
I hope this clarifies a bit why beyond all the current events & conspiracy theories out there-The Colombian riders pride and remain always "CLEAN-ER" than their counterparts around the world