Is the Marine Corps to strict with its enforcement of "proper civilian attire" while off duty?

All right, I'll give you an opinion from an old fart who drew his first issue of uniforms 54 years ago at Parris Island. Not only did I get clothing that was appropriate for any situation, but a seabag that it could be carried in that protected the clothing like a civilian suitcase. When my compatriots and I went home on leave after we completed our post recruit infantry training, we wore our A Greens for two reasons; first, as has been cited in this string, we only made $90 a month and didn't have the money to go out and get muftis, and secondly, we got a discount off the train fare if we were in uniform. If the Corps wanted you to have civilian clothing, they would issue them to you as they do those assigned to Embassy duty. As time went on, and, quite frankly, we started being harassed by anti war protestors, they started allowing us to travel out of uniform, but as always happens, some Marines started traveling in clothing that made them look more like hippies than Marines and the Corps became more restrictive regarding what civilian clothing we could wear. The CMC expected we would adhere to the same standards of dress we were taught in basic training. We would PT prior to breakfast, but a shower and change out of PT gear was scheduled before we went to the chow hall out of courtesy to the others eating there who may not have wanted to eat their meal sitting next to a platoon of sweaty, smelly Marines who had just done their daily dozen exercises. When we left training, you didn't go to the Commissary or Exchange in a dirty uniform because it was considered inappropriate to mingle with the dependents and retirees (of course it hadn't been long since the ladies were expected to be in dresses and wear gloves to the clubs).
The same standards applied off base. Marines are recognizable. Even 30 years after I retired, as a 73 year old with my now bearded face and civilian haircut, living four hours from the nearest base, more than once I am told "you're a Marine aren't you?". It's not my clothing or grooming, it's the way we carry ourself.
So I disagree. While on active duty you are no less a Marine no matter where you are, and the fact is, if you adhere to those basic standards of hygiene and dress, there will rarely be an occasion where you will be inappropriate.

While overseas during non-combat deployments, the strict code actually made us stand out. Greece was off limits as a port of call due to terrorist activity which was targeting US military. The ship watch was denying debarkation if you didn't wear the correct attire. I understand the need or want for professionalism, but prudence may be the best approach. Wear what the locals wear, blend in, especially while engaged in asymmetric warfare against a very non-conventional enemy.

It has always existed within the military. Some locations more restrictive than others. Oversees, special duty etc. require stricter standards based on how one is representing the Military and Country.