1) Catching a ton of short passes often mitigates itself in the yards / target metric because receiver catches a higher percentage of balls. Really low yards/target is result of really poor yards per catch, a really low catch rate, or some combination therein.
2) When Wes Welker was in New England, he averaged 8.1 yards / target (vs. Landry's 7.5 and 7.3 in Cleveland and Miami, respectively). The only year he was close to the seasons I mentioned for Landry (2010 - 6.9 yds/tgt) he shouldn't have made the probowl either
3) Julian Edelman never made the probowl, so not particularly relevant
Jarvis Landry is/was a good player and his current contract is fine - no argument from me there. That doesn't change the fact that the numbers for 3/5 of his probowl years are really poor for PB receiver standards. Both things can be true.