I don't believe dirt and debris on the lenses are a function of loss of internal pressure. While the scopes are nitrogen purged, and may have some pressure, it's not like high pressure gas charged shock absorber.
The lenses are most often dirty b/c of poor factory cleaning, or internal dust or anodizing that flakes off upon recoil. The problem is very common in scopes with etched reticles, as the pieces stick on the glass in the same plane as the reticle, and show up annoyingly large and often don't go away due to electrostatic adhesion. This shows up with no breach of the internal seals of the scope at all.
At any rate, I'm sorry to see the negative comments on the Conquest. I've actually heard this more and more the last year or so.
Products, like people, tend to be verbs. It's important to get a current weather reading when it comes to optics. Last year's scopes represent ancient history.
Scott