These “features” make MATE’s code more cluttered, sometimes there are bugs(1, 2), they waste space, time of development and increase the size of the ISO for no good reason. And they are going to be around until what… the year 2050? At some point they will be removed anyway.
These comments above confirm my suspicious that the MATE community is infested with trolls that want to hold the Desktop Environment’s development back, they are like some of the comments on the thread about the new default layout(good changes and improvements by the way).
Some of these comments are a red flag for me and I will abandon ship and stop giving feedback, good luck with the project, best wishes.