This is tiring already.
Ultimately, it's the decision of the list maintainer.
Either way some will like it, some won't like it.
Let's all just promise ourselves to deal with it by adapting to how  
it is or how it becomes. If that means having a messy list to read,  
or changing your mail / news reader agent or just eating the  
unpleasant, so be it.
Let's get back to more critical matters.

My final take is that the added characters do add up to a lot more  
packet traffic when you consider the size of the membership.
Clearly it's an easy/lazy solution to add the characters for some  
people's client software.
For others it's an increase in the signal to noise ratio.

If it's added, I expect some Rubyists to immediately make a title  
muncher to bite off the parts they don't like.
If it's not added, I expect the other Rubyists to immediately make a  
title prepender to add the parts they want.