I think you have a complete lack of understanding on how the club is run now (as do many other Gooners).
Firstly, in an interview last week with the BBC, Wenger stated that the clubs policy is to buy young and develop and thats it. I don't know why fans constantly go on about transfers as its been stated by the Manager that its not how the club is going to work. So we either get on with it or support someone else.
As people are pointing out, most people now think thats simply Wenger being scared to make an expensive mistake. I would also say the majority of gooners constantly make/made the youth policy excuse, when in reality its not at all true. The other issue is, Wenger didn't buy a young cheap defensive midfielder either, he got one whose barely played for 2 years and might just play a few games this year. With 3 expensive sicknotes already did we need another. I for one don't care about the name, the size of reputation or the cost of the transfer, I would have been happy with a free player if he was ok/good, but he didn't get anyone.
Denilson has NOT been good for 2 games, he was awful against Twente, barely got a single pass right, barely a tackle won, much the same against Newcastle, it was just less telling because Fabregas played great, and Fabregas made quite a lot of tackles and interceptions in midfield, it simply hid how bad he was. Denilson, 2 years ago was an attacking midfielder in Fabregas's mould, he is not defensive, is utterly useless at it and was up against a vastly weakened Newcastle side, he put in about 14 seconds of use in the box, but thats not good enough and won't cut it against better teams. Eboue had a great game, again, he was probably man of the match in the first Twente game, only player that didn't give up and created the goal, he was the only slightly useful player against Fulham but can't shoot to save his life, he created chances though, and tackled well, Denilson was in the defensive role(for some ridiculous reason) and was woeful, passed it to fulham every 4 seconds.
I do know how the club is run, its NOT THE CLUBS policy to buy youth and bring them through, its Wengers, one he's broken a whole bunch of times, so in that regards, its barely a policy, its when wenger feels the need he goes expensive, like any other club. We buy probably a lot bigger number of youth players than other clubs, and have many, many failures(hoytes) in amongst the few gems like Fabregas. Either way, Denilson will not cut it this year its that simple. Flamini wasn't great last year, and Hleb was entirely useless, we threw away the season last year with lack of goals in the last couple months. We've got some decent players in, Vela is class but so far has barely had a look in, like so often Wenger chronically underuses some players leading to others being injured all the time. The club states, every single season, the youth policy is not their idea, they will happily buy ANYONE for basically any price and Wenger does his own thing. Every year, even at Highbury the board all come out and say Wenger can get who he wants. he spent big on Theo, Reyes who wasn't that young, Rosicky, Eduardo, Hleb, Ade's not old but not young either. To say Wenger doesn't buy expensive, or older players, is utter crap, to say the clubs policy is such, when every year they publically tell Wenger to go spend some damn money on experience, is crap, to say its anything but Wengers reluctance to lose big is probably crap. We'd still have Reyes if we started him in the champs league final ahead of Hleb, who that year was miles beyind Reyes in quality, likewise Pires said he decided to leave when he was substituted over Hleb in the final after the red card, being that he scored 12-16 goals a year, compared to Hleb's 3 with 4-5 times the number of assists too. We lost two class players over Wengers love for Hleb.
AN average, cheap not even very good defensive midfielder would have done tbh, right now we have Denilson, who shouldn't be in the premiership, and possibly, remember its only possibly, a replacement in 2-3 months, its already cost us 1 loss in 3 games.