I'm not saying he did anything wrong, but it is a bit of a slap in the face. I think the US should have a policy of not admitting renouncers to the country under any status.
lol, overreact much? People change citizenship all the time for various reasons, finance, marriage, lifestyle, work etc. it would be crazy to block people from returning. Personally I'd take Singapore over the US any day of the week if I was choosing somewhere to live and had that kind of money(Singapore is an expensive place to live).
what happened to "land of the free", as in freedome to decide where you live and your citizenship?
No one can stop you from renouncing your citizenship, but if you do you are are an alien. Ask some aliens how easy it is to get a visa to the US. If you voluntarily put yourself in that category at very least you should be at the back of the line.