Lol criticising Amir that he is not Wasim is like criticising every batsman in the world because they are not Bradman or Richards.
As far as the assessment of Pakistan's bowling attack goes, there are two ways of looking at it, one more applicable in current scenario, and one not so much. If we go by what their respective skillsets and abilities as a whole, then it's a pretty dam good pace attack, one of the best in LO cricket at the moment. Irfan doesn't run through sides, yes that's not his job or skillset. He gets breakthroughs quite consistently in LO (mainly ODI) cricket, he often comes back in his second spell to break a partnership. 1-2 wickets per match is usually his return and that's what he is there for, not a 6fer.
Having said that, whether the skillset this attack has is relevant and applicable to the current tournament, given the conditions? Not so much. This is not their fault, this is a failure of epic proportions by the selection committee that picked a squad with 5 seamers and no frontline spinner, because they thought the tournament was being played in South Africa.
The PSL had plenty of spinners among the top wicket takers, yet none of them were picked. So asking Wahab Riaz to go and bowl cutters at Eden Gardens when that's not what his skillset is, and then criticising him for failing to do so is stupid. He should not have been picked, not because he isn't good enough, but because these are not the conditions for him. There should have been 3 spinners in the side, one frontline spinner, supported by Imad Wasim and Afridi.