You are wrong. I'm sorry to be so blunt, but that's just the way it is.
Actually, you're getting it all backwards. You are saying mountain stages that finish on a descent are more doomed to conservative riding than MTFs? How, by forcing the riders to attack from farther out???
About your 95%, let's look at great stages with a finish after the descent in the last 4 years:
La Thuile 2006, Morzine 2006, Granada 2006, Briançon 2007, Loudenville 2007, Bagneres-de-Bigorre 2008, Le Gran Bornand 2009, Grappa 2010, Madeleine 2010, Balès 2010, Gap 2011, Pinerolo 2011, Cordoba 2011.
Now if you feel like it, do the math relative to the total number of mountain stages finishing after a descent in GTs in those years. Then do the same math with MTFs. And then come back and tell me with a straight face 95% of those stages are doomed to conservative riding.