Dressing for a venue is in fact dressing for others. Basically, dressing for the appropriate activity shows that it engrained to wear clothing based on your social enviorment
I call BS on that opinion.
One example is that certain venues have a dress code and you need to obey or be denied entry. So are the "others" management? If so, then there may be a hint of truth to "dressing for others".
Another example; Let's say I know I'm going horseback riding, will I choose to wear a ballgown? No, I will dress based on my comfort level but not on my social enviroment. I could care less what others think of my choice. My choice is based on common sense.