It's just practicality. You sacrifice quality for consistency, the goal of elite clones is to mitigate that relationship. Like, if you ran seeds, you might have a heavy feeding 8 week pheno, a light feeding 11 week pheno, and everything in between. A few of those plants will be untouchable holy shit amazing keepers, others will be duds. When it rains, it pours, you know?
It makes a garden very hard to manage. So rather than take the time to do a pheno run, keep mothers, cull bad genetics, worry about this that and the third thing, just to get one monocrop of something that's all great. When you buy clones, you get that off the shelf, but it's not exclusive. It's just a short-cut, and the process of cloning is just part of any grower's lexicon. A lot of people don't have veg facilities, lets say, so it's cheaper to just buy a shipper of teens than bother doing their own propagation. You can turn out a lot of variety faster, which is a virtue in itself.
I prefer the old fashion way, just because it's more unique. It's the difference between writing original music and being in a cover band. Sure, people get dressed up and know all the words to the songs, they just aren't your songs. But it isn't for everyone, and I understand that, both tribes have their place. I love it when people grow my clones, probably more than any other aspect of cannabis. Smoking, growing, nothing compares to sharing clones of your own secret head-stash. It's like an unbreakable bond you have with the plant and the community that could very well outlive you. I think that's pretty groovy, worth every minute I spend doing it.