The only reason I'll often spend some time naked before getting into my street clothes is to cool down and dry off completely. It's a common complaint made about "old creepers" I've read here (though not yet made in this thread), that we don't get back into our clothes fast enough. Yet if you stop to think about it, there are real reasons why you will indeed see us older guys doing that.
For one reason, we're more likely to have the luxury of time, with no where to be in particular. I'm retired myself, so unless I have some specific appt, what am I rushing for?
Second, I really think our older bodies take longer to recover after exercise, for our heart rate to go back down, for our bodies to cool off. And believe me, if we don't take the time, we can feel it outside, when it hits you driving the car home.
Third, there's a generational difference. Most of my contemporaries would have taken gang showers back in high school & college, some had nude swimming classes in school or when at the YMCA, maybe been in the military during the Draft, and overall been raised not to be shy around other guys. If we look nonchalant & relaxed about it that's because we ARE relaxed, it's not the big embarrassed self-conscious thing some younger guys have going these days.
And I'm sorry if that's not what they do, but it's a men's locker room, and until someone posts signs to the contrary, I'll continue to behave as I always have all my life. Which BTW, always includes sitting on a towel when I'm bare-ass, for my protection as well as yours.