Yes, the ultimate success is to win the title, but not finishing any lower than 4th (with the exception of last year), is still pretty impressive when you compare it to the success (or lack of), from other Super coaches, from other franchises. Ian Foster achieved 4th, 6th, 7th, 6th, 2nd, 11th, and 10th, so Blackadder missing the playoff's once, does not put him in that category.
You've really got to compare apples with apples, if you are going to compare with previous Crusaders coaches. In the Deans era (and prior), the other teams got one crack at the Crusaders during pool play, and now all of the New Zealand teams get two (most of which are more than capable of beating one another on any given day). Blackadder has had to deal with the Canterbury quakes, and still almost got the title that year.
Whilst you tout the player of the year statistic, most of those players have had limited playing time, due to injuries, sabbaticals etc, and the percentage of Crusaders in the All Blacks has probably dropped too, with the rise of the Chiefs and Hurricanes players.
The number of All Blacks probably doesn't have bearing that it once had anyway; Chris Boyd (who had a great season with the Canes), failed to deliver with an almost total All Black backline, in the game that counted, against the Highlanders, who at the time, had three All Blacks in the entire squad.
I agree (as I said previously), that the current Crusaders squad looks a little underwhelming. I don't think they've recruited as well as the did back in the Deans era.
I do rate Gibson as a coach, but if Blackadder's coaching tenure is deemed to be under performed, then should he not take some of that too, as part of the setup for a few years?