Would you like it if someone bought a house that you built with your bare hands, then said they built it themselves?
Yeah. The architect that designed it doesn't deserve any of the credit.
IF you sell 100% of the IP, you might as well have not made it. Whomever owns the IP made it.
It can be good or bad. If all you enjoy is making the games. finding someone to sell the IP to can be good.. make a game every 3 months and sell it for more and more each time as the person buying realizes how good your games are.
Happens all the time in the music biz. Granted, those songs are written in an afternoon in most cases. But they get a lot less for them too.