To work full time on Anki, I need some way to pay the bills. Currently AnkiMobile is able to do that, but if one day its sales are no longer able to cover costs, I would need something to fall back on, and AnkiWeb is a potential backup source of revenue. For this reason, I’m afraid I don’t think giving it away at this point would be the smartest move.
There are third-party sync servers out there already, largely based on the code from the computer version, which you may wish to explore further.