This. I honestly don't think the board are tying Wenger's hands in any way. I'll accept that he is subject to economic pressures - but my reading of it is that he imposes these on himself as much as the board imposes them. I think that the manager's philosphy has always been to pay what he believes is value for money in the transfer market, and that this - together with a self-belief that he can bring new developmental players in to fill the gap left by sales at the top - means that he is philosophical about his best players leaving rather than putting pressure on the board to cough up what they might demand to stay.
Where I am prepared to cut Wenger some slack is that I do believe that he regards himself as a custodian of the club, and I think that he is hyper aware of the effects of paying what he regards as inflated wages. But against this, I think that he is as much to blame for any lack of flexibility in this regard as he takes too many risks, pays mediocre players too much, and slavishly sticks to a policy of wage equality in the mistaken belief that this fosters squad unity/loyalty.
The fact that the board supports Wenger in his bids for potential (we pay top dollar for these inds of players - possibly more than anyone else) suggests to be that he is given more freedom by our board than most other managers, not vice versa. Kroenke has said many times that he backs Wenger to the hilt - and commentators have said that because of his lack of knowledge about the game he trusts Wenger 100% - and why not, when the guy has delivered profitability far more consistently than trophies in recent years.
At best, Wenger enjoys unrivalled power at our club, at worst, his motivations and those of the board are, IMHO identical. Unfortunately, this has resulted in the manager's acceptance of not winning things.