Bakhtiari is not only an alternate, he's a second alternate. Same with Clark. It doesn't help they have played on a losing team the past two years.
Most Pro Bowl names seem to be sound choices, but there are always a few that get in on reputation while some younger players are overlooked.
All Pro, with the AP version the most commonly cited, is a better measure. But how deeply informed can those voters possibly be as to the performance of all players on all teams based on first hand observation? Not at all. They are probably in tune with professional and media concensus, but it seems that consensus is increasingly informed by PFF and advanced analytics. While that is better than a glace at the stat sheets and a shot in the dark, which is what you get with fan voting for Pro Bowl, I remain skeptical that All Pro gets it as close to right as is generally recognized.