Other countries have very high standards regarding who gets let in. Take New Zealand for instance....http://www.immigration.govt.nz/migrant/stream/alreadyinnz/residents/nextsteps/prvrequirements.htm
Even Australia & Canada don’t just throw open their doors; they have the same welfare we do, and want to ensure they don’t end up on them ASAP. In our country, the wealth re-distributed by that welfare has created a huge false economy that is used to keep whole states afloat.