Please don't take this as a indictment of either baseplate compasses or liquid filled, I own about 20 that have one attribute or the other (real Silvas,Suunto-Recta,Brunton-Nexus;8099,15TDCL,Global,Matchbox).
I will note that the largest buyer of Compasses in the world is the US Government. Mostly the armed forces.
A couple of comments;Apparently the US Army many years ago found that the liquid was the most common defect in their repairs.
As has been discussed in other post some of the military aspects are not needed by many non-military users, notably a mils scale.
Personally I think that self illumination is a good feature for MOST users if they know it or not.
All that being said, given the numbers of Lensatics in the field and the number of years in use, the US Military is either knowns something about it or is bone-headed (could be either, I served 6 years in the US Army and learned LARS,the M2,Lensatic,MGRS, etc,The right way vs the Army way).
Lensatics are heavy (as are some military prismatics, G-150,M-73 etc), but very rugged too.
Now nothing is GI proof.
Yes the military did experiment with the 15TDCL (good choice), but when I did the military it was well known that in ALL the schools especially RANGER school, that possession was contraband.
In the field you carry what they give you, but anything else too.
And you are right a lot of soldiers,airmen,marines carried baseplate type compasses.
So personally (and without any DATA to prove it) I feel that the Lensatic is MORE robust than the baseplate compass.
Certainly I could be wrong, wouldn't be the first time.