I'm not saying anything one way or the other what we "should" do, just answering the question "what would make private parties adopt renewable energy". My answer ("money"), in fact, agrees with you: whether it is artificially cheaper or naturally cheaper doesn't matter.
However, I think renewables would be cheaper even without government subsidies. Texas had large wind farms over even 15 years ago. I don't have any information about subsidies on solar panels, but given that the cost trend is halving the price every <n years>, that's pretty powerful. I think you could remove the subsidy and solar panels would still be competitive, and even if not now, than in one more halving period.
It’s also hard to detangle the effects of local subsidies vs those in say China which are also driving down costs of solar.
Really in context my question was “What would motivate the private sector in the absence of government intervention”. The comment I was replying to was clearly setting up a contrast between letting the “private sector” solve it instead of “hamfisted government policy.”
Really those two aren’t separate. The government even when it “overreaches” in the eyes of some rarely tackles large projects on its own. Most of what it does is regulate, tax, and inventive the private sector to attempt to achieve some desired outcome.
However, I think renewables would be cheaper even without government subsidies. Texas had large wind farms over even 15 years ago. I don't have any information about subsidies on solar panels, but given that the cost trend is halving the price every <n years>, that's pretty powerful. I think you could remove the subsidy and solar panels would still be competitive, and even if not now, than in one more halving period.