Yes. Yes they do. Quite a lot. They take up space reminding me how the alphabet works. This "C" is to indicate that the following programs begin with the letter C. This "D" shows that the next items have names where D is the common starting character. And so on, and so forth.
Actually, I just looked at this .. and they have a function (who knew??). If you click then it shows the alphabet as a block in a dialog and you can jump to a different letter!
I'd still get rid of them (or push/float the app links to the right) and save the vertical space.
The behaviour you found out is an inheritage from the good old Windows Phone 7.
I use it quite frequently, because when I'm going through the list it's usually because I couldn't reach to the program I wanted by just typing the name. So if what I need it's under "W", then it's a way to be quicker.