They had 6 stores in Canada before they opened their first store in the USA? I wonder what made Canada such an attractive market for them (or what made the USA unattractive). They got into the USA in 1985, when the USA currency hit its post 1973 (floating) exchange rate peak. I wonder if the high exchange rate was a plus or minus from IKEAs point of view?
Not sure if it's what happened here, but - companies will sometimes "test the waters" in Canada and iron out the kinks before coming to the US. If they screw up, it's on a much smaller stage, and it can be fixed more quietly.