He is portrayed as sensitive and enlightened —sickened by war, and therefor more noble. Contrasted to York, another sensitive guy with little like for war, York does his duty and this slime ball deserts.
Even if he would have claimed new found contentious objector status, took the heat, went through that fought process, he would not be viewed as low as he became. Violated his oath, walked out, collaborated, and then promoted to hide his failed character. A true progressive youth.
I think you captured the Liberal view of what the military should be.