GPON is the most commonly deployed FTTH technology and is not symmetric, though it should be much closer than a 20:1 down:up ratio, much closer to 2:1 IME.

Actually, the hardware symmetric capable, but they don't provide symmetric service (yet?).

I think the two reasons are market segmentation and preventing people from running services from their homes. 50mbps is enough uplink for what I do, and I don't care about providing services or self-hosting from home.

I have enough experience to run my services somewhere else on an isolated network and absorb the mayhem outside my home network.