Top Londoner wrote:Did I read it correctly somewhere, that we have shipped out 17 players in the past few months?

We have but the number is not as significant as the media makes it out to be.
Let's analyse the departures:
1. Martin Angha (
CB) - insignificant departure, youngster, no league appearances for us
2. Jernade Meade (
LB) - insignificant departure, youngster, no league appearances for us
3. Craig Eastmond (
DM) - insignificant departure, youngster, four league appearances for us in 2009/2010
4. Conor Henderson (
midfielder) - insignificant departure, youngster, no league appearances for us
5. Chuks Aneke (
midfielder) - insignificant departure (loan), youngster, no league appearances for us
6. Sanchez Watt (
striker) - insignificant departure, youngster, no league appearances for us
7. Joel Campbell (
forward) - insignificant departure (loan), youngster, he hasn't player a single game for us
8. Vito Mannone (
GK) - insignificant departure, we do need a third senior GK though
9. Andre Santos (
LB) - insignificant departure, we have two LBs and Verm can cover there too, also he's fat
10. Denilson (
midfielder) - insignificant departure, he's been out on a loan for two seasons so he's been unavailable since summer 2011
11. Andrey Arshavin (
forward) - insignificant departure, no league starts for us last season
12. Marouane Chamakh (
striker) - insignificant departure, played zero league games for us last season, also had no confidence
13. Sebastien Squillaci (
CB) - semi-significant departure, terrible CB but better than no CB and we need a fourth one
14. Johan Djourou (
CB) - semi-significant departure (loan), he was out on a loan last season too but we need a fourth CB
15. Ignasi Miquel (
CB) - semi-significant departure (loan), even though he's youngster, we need a fourth CB
16. Francis Coquelin (
DM) - semi-significant departure (loan), we need cover for DM
17. Gervinho (
forward) - semi-significant departure, made 12 league starts last season, got five goals and three assists, could cover on the wings and up front
So there have been five semi-significant departures and three of them are due to Wenger not signing a centre-back.