Well, it might also have not worked (e.g. someone sells a client software they don't yet have, hoping to build it in the meantime before the delivery, but fails to finish it for whatever reason -- it might just take more time, or he finds out he doesn't have the needed skills).

That would have made a client wait based on a lie ('we already have the software') and depend of them (when the client could have gone shopping elsewhere where they do have the software he needs), which could have cost millions in damages (e.g. failure to get its products to market, because the component he though he bought didn't actually exist when it was supposed to delivered)...

MITS were not dependent on Gates and Allen for BASIC; MITS didn't even have plans to have a BASIC interpreter. They were approached by Gates and Allen out of the blue, and had no contract in place If they had not delivered, it wouldn't have set MITS back at all, though it certainly would have not helped sell more Altairs. MITS would have (likely was) free to entertain offers from other entities.

MITS might not have been.

But parent said they can't see anything bad with the behavior (lying about having something you don't have, to make a sell, and rushing to actually make it before the delivery deadline).

And it's something that can surely have bad (to very bad) results -- if you fail to make it, or if you make something sub par to what you promised.

hustling is a privilege.

So is posting on HN. How does that make it wrong?

just saying if you have no excuse for failure you just have to hustle, others blame their failure on others and don't see how others hustle to be successful,