Well it's Begelton, and no one is saying he is going to light the world unfire. It is a very logical stance to take that he has as much if not more of a chance to catch on than a Day 3 WR picked this year given all his experience on the professional level albeit in the CFL; which is a higher level of competition than quite a few college football programs see, especially the smaller school guys.
Also no one is saying they'd have picked Begelton over a slew of WR in the draft this year. Shoot I could list easily a dozen or more before I'd say I'd go Begelton over them....matter of fact here is a very quick list of guys I'd have picked over Begelton from this year's draft that come quickly to mind:
Jeudy, Lamb, Ruggs, Pittman, Aiyuk, Laviska, Edwards, V. Jefferson, J. Jefferson, Gibson, Hamler, Reagor, Higgins, Claypool, Mims, Bowden, T. Johnson, Davis and Duvernay
Few that come to mind I'd have considered taking Begelton over: Gandy-Golden, Reed, C Johnson, Hightower, Cephus, Coulter, Osborn, Hill, Hodgins, DPJ....only one of these guys went above the 5th round if memory serves (Gandy-Golden).
I don't have crazy expectations for him...but I also have realistic abilities to apply a Day 3 grade on him in a discussion of what value his addition is similar to.