Cause someone could sneak in an inflation bug?

Bitcoin has a 15 year record of running as it is. You change the code this much, you start over from zero.

Because you can trustlessly atomic swap for Monero and back. Get off your maxi horse and use Monero if you need base layer privacy. Nobody is saying. Sell all your Bitcoin for Monero. Reasonable people say. Sell 1% and hedge your privacy risk and have fungible money ready to spend.