Sorry to hear about how you were treated with xenophobic remarks. No humans should be treated this way. I had similar if not worse experiences like you what have been through.
When I shared my personal views about the Foreign Sports Talent Scheme(FSTS), I was being attacked by people who labelled me xenophobic, stupid, a fool and an idiot. Someone even hurled vulgarities at me and ask me to leave the country. So even a local born citizen like me are vulnerable to vicious attacks.
As for your point about the risk of local talents who do not return after being sponsored by the state, this risk is universal, it can happen in any country, especially for developing countries like China where bright athletes migrated out of their own just when they are in their prime age to “repay” the grace which the home country has nurtured and sponsored them since young.
For the case of Singapore, from my knowledge, so far no local born athletes have known to break their bond and choose not to serve our country if they could.
The reason for the unhappiness for the FSTS is that our Govt could have chosen the easy way out in order to win medals, the money could have been spent to nurture eager and hardworking local talent instead, talents of which we are in no lack of. E.g. if Quah Zheng Wen has more funds to be trained longer in the US, he could even be on par with Schooling. If SEA games gold medallist Aisyah had some funds and good coaching, she might have a good shot for a medal too, instead of spending a lot of efforts just to get a crowd funding of 14k.
The FTs are paid a salary, while the local talents have to fork out their own money. Most reasonable guys are not blaming the FTs, as who will work without a pay? But it’s the locals, out of true love for their own country, will be willing to go to the extra mile without any expectation of being compensated.