Abusing might not be the right word but you are taking advantage of the unethical system because you know it requires persistent devaluation of the money. But you bring up a fair point. By borrowing fiat you are contributing to the expansion of the money supply which could potentially harm others. This monetary supply expansion will happen with or without your involvement and your involvement is a mere blip but I think philosophically it is a reasonable question. I guess it comes down to if you think the positives outweigh the negatives.

It's hard not to follow the incentives, and there are incentives to short fiat. To not follow the incentives you'd have to break your mind and become what the communists wanted people to become, an incentive non-following creature. Such a creature would end up taken advantage of, enslaved, abused and poor.

Shorting fiat also involves liquidation risk, so you're paying a price for it in the risk and the higher your leverage, the greater the risk.

Perhaps the idea that borrowing fiat to buy bitcoin is unethical is a psyop sowed by the powers that be to keep us from stacking more? Just a thought.

I tend to view it as a game. The goal is to maximize your score, which is the amount of sats stacked. If you don't play it well, others will and you'll be their victim.