How hard is it to forbid any transaction with unreachable code? I mean, putting this restriction in the protocol not in some implementations of the mempool.

Let's say it's the perfect mix of altruism and self interest:

Bitcoin needs both nodes and miners. Miners are there for their own personal gain. Nodes yield no personal economic benefit but are vital to the community as a whole, hence more altruistic. Bitcoin needs both aspects to succeed, it's not just self interest or just selfless altruism. It's both. Yin and yang. Left and right.

Bitcoin is for everybody, not for conservatives. Bitcoin doesn't care about your political views, gender, race, or anything. Bitcoin is the ultimate inclusion.

Bitcoin is so great because it is the union of left and right. It is supported by the community of nodes ("left") and miners seeking personal gain ("right").

Learn coding if and only if you enjoy coding. Simple as. If you love it, it's never too late.

I don't think there is anything explaining the lack of Bitcoin spending other than Gresham's law. The more people save in Bitcoin, the more they will eventually need to spend it or at least convert that Bitcoin into fiat for spending that.

Do you track all the cash you spent and how? Bitcoin (esp. lightning) is cash.