Since when is incentivizing low cost renewable energy horrifying?

Bitcoin cares not for how much energy it uses, just how valuable the energy it uses is. This does not make more energy available to anyone else or reduce the price.

My first link shows that Bitcoin consumes roughly 40GW and my second link shows that the UK roughly does too.

There are a lot of ifs and buts here ... but the amount of power used to support the BT mechanism worldwide is roughly the same as the power consumption of the entirety of the UK.

Because every unit of electricity causes climate change and burns resources (even renewable sources of electricity - they just burn them slower). From a societal point of view we are dumping huge amounts of electricity and resources into a hole to accomplish nothing that couldn’t be accomplished with a database and a trusted third party at a billionth of the cost (or less).

The vast majority of transactions are speculation on what other people might pay for a bitcoin (i.e., a line on a spreadsheet). And even then, that speculation and trading often occurs on secondary markets which rely on trusted third parties - thus rendering the entire ordeal even more pointless.