While the world may have been a different place during the era you describe, the reason of emigration has always been the same and that is to realise the dream of building a better future.
I see no difference between the Ah Tiongs who are arriving today and those that arrived a century ago. They want to improve their lot just as your forefathers did many years ago.
Where did you get your stats for emigration rates? Please advise.
Yes, all yearn build a better future, but most importantly, where? In Singapore or back in China? If I was a PRC migrant who wished to return to China after I made my big bucks, would I care if Singapore ended up a radioactive wasteland? To those living in Singapore, should we care? To those people (whether singaporeans or not) who want to migrate to australia, canada or the u.s. do they care?
As for the stats, I pulled it out of thin air. Was I as bad as Singstat?