such a waste
That's your assessment, which doesn't really matter as long as there's still demand for mining ASICs. If that's the case it really is a waste because destroying them will just cause the demand to be satisfied via newly produced ASICs instead
These were ASIC computers which were stealing electricity, all they can do is mine crypto, so what else are they good for except getting squashed?
Get back to me when that happens
Only in the short term. Difficulty adjustment makes the total mining power irrelevant over the long run.