I think you have misunderstood the point. As Masterminded has explained, we are talking about the time when either these players are signed, or when they are offered contract extensions. It just doesn't make sense to argue on the one hand that the club and the board are obsessed with making money rather than achieving success on the pitch, and on the other hand to suggest that they are paying over the odds for young players and their subsequent wages for the hell of it. Any contract extensions that these players are given are on the basis of the market, and either the existing or potential demand from elsewhere for their services.
It is misleading to apply hindsight, to point to the current crop of players who have underperformed and can't be shifted because of their wage demands and to conclude that we paid over the odds at contract time. This is the same as looking at Cesc or RVP at the date they left the club and concluding that their original contracts were too low. Generally, players are paid what the market dictates at the time they sign.
What Arsenal, as a developmental club, may have done is to stick too many eggs in one basket - hence the current glut of difficult to shift players. What they cannot be accused fairly of is willfully paying over the odds at contract time.
The other issue that needs to be remembered is that we are Arsenal centric, and dwell on our players. Every club in the league has players whom their managers hoped would succeed, but who have failed to do so. We may have more than most, but in a sense that is because of our fairly unique position - rich enough to be able to pay for prospects - not rich enough to reward the best talent. Sure the club can be criticised in hindsight for taking too many risks on unproven players, but its a criticism that relies largely on hindsight; forgets that despite noteable failures, one of the manager's greatest talents is creating top talent, and ignores the inescapable fact that players sales are and have been crucial to the club's financial stability.
Finally, I am a football fan and have venom for players that are disloyal to my club. Simple, really. I have always said that its a free world and players are entitled to chase whatever money is available. Doesn't mean that I like it, though.