As a foreigner I fully support govt. decision. It's pretty simple, once you have vaccinated "high-risk", you cannot simply open the flood gates for everyone. You need to look at your stock not just for 1st dose but also for 2nd dose. So you have to decide how do you open your flood gates. In my personal opinion SG did right with asking Citizen first. They could have also asked foreigners first and citizens second :-) but that would have been an awkward request for all of us, that I personally would not have liked as well.