First of all, if the run plays are getting out to your boundary often enough to affect things, you've got much bigger issues defensively than a corner that's not great vs the run. Second of all, just as a personal preference (and an absolutely huge critic of tackling in the entirety of North America), I'm paying my corners to cover in a passing league. Given the chance, I'd love a physical tone-setter on the boundary, I just don't lose sleep if I don't have it.
Also, to CBA's point about tackles after completions, the apparently-flawless Ronald Darby allowed 30 yards more than Gilmore after the catch on 103 less coverage snaps. Darby actually missed as many tackles last year as Gilmore (with 8) on 160 fewer total snaps. While I'll grant anyone that Darby has better form as a tackler, it did seem as though folks were focusing on the soon-to-be free agent scapegoat rather than picking up on failings elsewhere.
For the record, Corey Graham led the team with 14 missed tackles.