First of all I would guess that most people carry for self defense rather than furthering the cause of OC. That said, carry no matter the mode.
Secondly I like to CC my BUG so now I won't have to stow my BUG when going into a restaurant.
Thirdly there are times where OC-ing gets you in trouble in certain circles. For example, when I take a customer out to lunch I am officially on the clock and my employer is a big ANTI. So while my customer might not mind me OC-ing if word got back to other employees or managers I could find myself out of work. So to CC, I will still be carrying (legally) and no danger of losing my job. There are also some family members that are anti and to keep the peace at their birthday celebrations (their home) OC is a no-no. CC allows me to still be able to defend myself without causing a stir by either not showing up in the first place or showing up OC-ing.
I think that some will stop OC-ing and revert back to CC. For sitting in a restaurant I don't think it matters much, but for walking the streets I prefer the deterrent of OC as well as the quicker access. So in places where mugging or attack are more likely/possible I prefer to OC.
Edited to add: For restaurants posting no-guns signs I will still mostly boycott them.