First of all, DovBear is the second-most vile anti-Jewish “Frum” blogger out there and should never be quoted. Ever.
Second of all, (this is mainly towards midwesterner), if you look up the Mekoros, most of the Nihugei Aveilus during Sefirah are because of the Crusades, not R’ Akiva’s students, and were instituted well after the time of Chazal.