If you get paid hourly then perhaps. If it is irrefutable that its your fault/bug then you should feel obligated to fix for no extra charge/hours to them.
Currently illegal in most if not all US states. When an hourly employee does work, they must be paid for all of their time.
I certainly wouldn't want to see this change. Way too much room for abuse on the employer side. I think the current remedy is sufficient (if any employer thinks someone is screwing up too much, they can fire them).
After any salary raise, you will have less money at the end of the month than you did before.