[CitrusFruits]

I worked at Dropbox briefly, and I asked this too. The answer was basically that they tried it (multiple times IIRC) and every time it ended up being a net negative on their ARR since it siphoned enough of the user base away from their other options. I think, also, the sort of user that uses less than 2TB isn't their "core" customer profile (think photographers, videographers, artists, and musicians).

I was bummed, but for a publicly traded company its a little hard to argue with the logic.