Did I say I like Bonk better - I like him better for the Flyers.
When you rank two players in the same tier, then you draft for need, you take BPA when there's a clear difference.
At the time of the draft Perrault was ranked higher by popular consensus, but if the Flyers have confidence in their scouting and projected them as equal value (drafting is basically about projecting a player at 22 years old) then they made the right choice for them.
I just value defense more than a lot of people, I'm wary of all these "advanced metrics" where a player is ranked 99th in offense, 1% in defense and 95th in WAR, something tells me defense is being undervalued. Same way when people go gaga over PP scoring, but ignore PK value - even though they're mirror images (the key stat is the net of special teams, i.e., do you score more than you give up?). So to me, two way D-men have more value than to most people.
I don't take Bonk's PP scoring that seriously, while it shows he may have value there (and what's wrong with a D-man in the bumper slot if he's good enough at it?), I've always said it's overrated at lower levels where the windows are large. But he also improved significantly at ES, especially since he returned from the WJC where he was the youngest D-man on the Canadian team.