The B-segment is most definitely not a lost cause! Here in Oregon, gas just hit $3/gallon and is still climbing. The reprieve after the last spike (to nearly $5 per gallon) is ending. There's going to be another wave of small car sales, and people who bought Escalades after the last price spike receded are going to begin whining again.
And as for Canada, sales are down 25% from what? Luxury SUV sales are up 4.1% from what? That doesn't mean that luxury SUVs are outselling subcompacts. To the contrary, by looking at the top ten vehicles, it looks like B-segment cars are the second-best-selling segment in Canada after C-segment cars. Only one midsizer is on that list, and it's #10.