McDermott's D has given up a good number of long runs. It's also stuffed the run a good number of times.
It's a passing league and it seems to me McDermott defends that first. Giving up a couple of chunk running plays a game doesn't cripple the D.
It does "skew" the numbers in "yard per rush" but ultimately the defensive scheme is to limit the TOTAL yards against and TOTAL points against.
There has been a number of opponent drives that ran the ball on 1st and 2nd and were left with a 3rd and long(ish). The 3rd resulted in a punt.
Your post is a prime example how a certain stat, while looking horrible, is not an issue when taken in context to the overall play.
All that said I will just have to accept all the "McDermott's D sucks against the run" in GDTs every time an opposing RB rips a 30-yard run.
It's just the price of doing business for the D, plus most of those runs can come down to a well schemed D just missing a gap or tackle.