No, it shouldn't. That's why, if you use Firefox, you should download the add-on for Xinha Here! and use it -- it's similar to WordPress options, and it's not that difficult to learn. (Press "Post Reply," right click on the reply box, and select "Open Xinha Here!")
And yes, it's annoying when comments are lacking simple HTML codes for quotes.
That would be a nice fix, and a huge enhancement. The one that I am suggesting would be much simpler, though less useful for non-HTMLers.