I think you know the answer to your question of why certain technology must be outlawed or taxed more. It's because by the time the technology becomes cheaper than fossil fuels we will have already done the damage.
I'll meet you half way and say, lets just get rid of all the implicit subsidies for fossil fuels that already exist and then tax people on the externalities they create. Hell, that in and of itself might be enough to make renewables cost effective.
I'm reasonably sure we're past the point of no return, so it might not even matter.