Doesn't seem to be a problem for me. I mean maybe if I added one it will raise the levels of "engagement" on my profile by a lot more but that level is already high enough to give me a steady stream of new work so I really have nothing to gain.

I wouldn't actually mind adding a picture now (I had a reason not to add one at the beginning, but this is no longer a problem) but at this point I will refrain from doing so out of principle to not show them an increase in their analytics data and encouraging their terrible practices.