They don't until things break, your app can't handle the amount of requests coming in, can't insert and fetch data in a reasonable amount of time, etc. It's at

They don't until things break, your app can't handle the amount of requests coming in, can't insert and fetch data in a reasonable amount of time, etc. It's at this point that shit falls apart and the manager starts to care about these technical choices and all of the time and money that will be needed to be spent to rewrite. Call it maintenance costs if you want but those costs are directly affected by the technology decisions you make.