Adultery is still a violation of the UCMJ, and sexual behavior is a major factor in unit cohesion. We have long forbidden military members use of government equipment (particularly computers and computer networks) and, while I was in the Navy (’95-’07) the NEX and MCX (Navy and Marine Corps exchanges) did not carry pornography. I don’t know about AAFES. This was typically supported by officers and senior enlisted. Mid- to Junior level enlisted did not like it. The fact is, character matters and it matters tremendously in combat. Encouraging behavior that corrupts character (gambling, excessive alcohol, sex) is contrary to the military’s best interests. I know there are those who think these are “manly” vices and indicate a robust military. I did not find it so.
Of course, I was a chaplain, so I tended to see those negatively affected by these vices. Those “positively” affected didn’t come to see me.