What you say is true, but I meant the product owners are the one who don't fully weigh the cost of their decisions.

I once tried to explain to a product owner that we should be careful to document what assumptions are being made in the code, and make sure the company was okay committing to those assumptions. Things like "a single order ships to a single address" are early assumptions that can get baked into the system and can be really hard to change later, so the company should take care and make sure the assumptions the programmers are baking into the system are assumptions the company is willing to commit to.

Anyway, I tried to explain all this to the product owner, and their response was "don't assume anything". Brillant decisions like that are why they earned the big bucks.