I spoil mine and people do make comments, but I don't care. I could be doing worse things!
I think you can spoil them too much to the point it affects their behavior. But, I think you can have a perfect balance of spoiling them AND teaching them to behave. That's always what I strive for! Jake is spoiled rotten, but he listens to me and is well behaved.
Honestly, I don't care what people think. My son-in-law makes alot of comments, and I don't like him that much anyways so it gives me good reason to tell him to shut up and mind his own business.