By that warped (anti)logic of yours, tractors have reduced the number of farmers....Combines have reduced the number of farmers.....Good seed has reduced the number of farmers....Fertilizer has reduced the number of farmers....You wanna argue the value or need of any of those?
No till has kept farmers viable, and in that regard, kept the numbers UP instead of the ridiculous notion it's reduced the number of farmers. Without improved technology, we'd all be out of business. Sticking with old world methods might make you feel good, but they don't feed the bulldog. Myself? I'd rather stay up to date, keep improving my craft, and advance my lot in life rather than stand pat, be left in the dust, and become an outdated part of ancient history.