You should have pointed this out to the FA.

Not saying the guy who originally took your seat deserves a broken one...but perhaps there were SAs who would (should) have taken the broken seat. And as much as I'll be criticized for saying this here, as a smart business person I'd rather p*ss off a 2P or 1P than a 1K...so perhaps forcing a trade with those folks would be an option.

Or depending on the time situation, they may have been able to call a mechanic.

On this topic, whenever there is a seat malfunction, I always inform the FAs who are able to write up the problem so it gets fixed.

On a recent SIN-NRT, both 16A and 16H were broke--no recline. When I continued on to LAX with the same aircraft, the seats were working...so evidently maintenance fixed them during the short 45-minute turnaround.