I don't think zero immigration is the answer either lol! Balance and moderation are the key principles, probably to the numbers of the 80's: why would we as a society continue to support the influx of 26,000 people a month when there is no job creation (or it is less than the labour growth)? Isn't this the definition of insane? Even more so when it is considered that people without jobs have social benefits and create a massive draw on the system so that it cannot do anything else (i.e. address health funding, soft service, infrastructure etc)

The reason that business now supports high immigration etc. is that their tax rates are much lower than they used to be, every new person gets a pot of taxpayer money to spend on consumption and keeps getting it even if the business doesn't create jobs to put them to work, it pressures down wages so there is more at the top and the government will do things like create the guaranteed income for non-employed  rather than reduce immigration.