I think the changes to carrying capacity fell under, if not "change for the sake of change", then "change we didn't even think about for a minute".
I mean, I assume they didn't change carrying capacity from sense to nonsense just because it would be different, but it's the only change in 4e that I absolutely can't defend from any standpoint - it needed either less text (say, just its first line, where it says "You can carry whatever you want as long as the GM doesn't think it's stupid") or less change (you know, just using the version from 3e), but instead they went and supplemented "well you can carry anything within reasonable limits" with rules that technically prevent dragonborn from riding on any kind of mount ever.
From my viewpoint, they changed it from a terribly complex system to a simple and intuitive one. The 3rd Edition version was just difficult to deal with, and required constant looking up to keep track of how burdened a character was. The 4E version is easy to handle and calculate, and lets you preserve the concept of a carrying capacity without having it completely bog down the game.
I mean, I'm rather amazed to see this called out as an example of 'pointless change', given that my friends and I viewed it as one of the most pleasing surprises of 4E. I can certainly accept it if you disagree with that - but to, again, simply dismiss my viewpoint (and that of the designers who felt this was an improvement) as nonexistent... well, it bothers me.
Rather than address the opposing viewpoint, this entire argument attacking 'change for the sake of change' is simply an excuse to dismiss the other side without conceding them a right to their own opinion. It is almost worse than the 'bad-wrong-fun' approach: you aren't just saying that my opinions on gaming are wrong, you are trying to claim they don't even exist.
Now, that might not be your goal - you might genuinely be unaware that there is an opposing viewpoint on these matters. And that is the very problem with this argument. "Change for the sake of change" gets thrown around constantly, and the majority of the time, it just isn't true. People have
reasons for what they do - as has been pointed out, when the designers made the decisions they made, they genuinely felt they were making good decisions. You can disagree with them and feel they made mistakes, but there really is no basis in reality to simply assume they were just randomly altering things without reason. And until one does put aside the 'change for the sake of change' viewpoint, and acknowledges that the designers may have had reasons for what they did, it makes it impossible to have a genuine discussion about those changes themselves.