It's not about being bitter. I am thankful I was born in Singapore and had I not been, I would not be the person I am today.
The decision is not regretting one's previous citizenship, but wondering whether it is wise to
continue citizenship.
GEP would be less of a scam if 1) entrance was not merely based on an tutorable exam 2) it identified kids with actual aptitude (and who, having their gifts bloom late, might become victim of a 'vicious cycle') as opposed to kids who are merely doing well in their previous non-GEP environment 3) relied (like the college application system) on teacher recommendations that actually looked at real intellectual passion and a drive for learning.
Maybe the secondary school entrance process should also make kids write "why school X" essays, just to give them a small taste of college applications.
That would help weed out the kids who go to elite secondary school X simply because their parents have been pushing them to do so. PSLE Common App, anyone?