I've seen this happen more and more, but it's not a bad thing.
You learn as a developer by workin on passion projects - even if the game never finishes, or comes out - that's not the point. The point is you flexed your muscle, tried out new ideas, and learned from it. When it stops being enjoyable to work on, there's no reason to trudge on - nobody will like the end product; especially not the creator.
What I liek to do when I'm feeling burn out, is just take a short siesta, and then come back to th stuff I was working on with a fresh slate, clean brain - no clutter.
Sometimes, the new perspective sheds light on things I took for granted.
sorry for the text wall, hope you got what you needed out of th game creation phase! Good luck in your future endeavors
cheers ~