It's not only that AGA was late. It's that when it was released to the masses, the machine (A1200) needed expensive laptop hard drives, had no Fast RAM, no CDROM (yes, massive crappy games like Myst etc sold quite a few PCs), no in-built software modem... to name just a few problems that hindered Commodore from keeping its user base.
And after all, the above are things that most people ended up buying within a little time from buying the A1200 as its shortcomings were obvious. The A1200 should not have been meant to be another C64. Anyway that's history...