The simple reason is that McVay knows them and they know McVay's offense.
This is assuming of course that McVay prefers them at all (he didn't choose the roster in DC; he just worked with what he was given).
I also believe that Jackson is a likely target because he's a California boy and would probably like to return to his home state.
So I see two (maybe three) good reasons why Jackson would be a fit.
Of course a big decision will be about Kenny Britt. But if the money is the same, I'd take Jackson. He is a home run hitter. He and Tavon in the same line up gives the Rams scary speed, although not a lot of size. That says they need a good all around TE.
