28"??? Which airline offers that? I doubt even Ryanair is that bad.

The industry standard is 31" - 32", which is exactly what AC offers on most of their planes. Nearly all of their planes have some seats with a 31" pitch, although most of the seats have a 32" pitch. The Embraer are the exception: the 190s have a generous 33" pitch, and 4 rows of the 175s in front of the exit row have a 34" pitch.

I am sure they have analyzed the Y+ concept carefully, and there is likely a sound business decision for not adding it to their fleet, but the excuse that they already provide more space is not true.