Federico mentions usability issues when trying to ban people from planets. I haven’t done any research, but personally think banning someone is a corner case functionality. I have never needed to do it on any of the planets I read.
What is striking to me when looking at the planets side by side though, is how unreadable the SUSE feed is. I can almost hear people say “but look how much information is shown on the right and you only see single post on the left”. Since when is packing as much text into an area a good thing? You will be scrolling in any case, and just look how long the lines on SUSE planet are. No padding for the paragraphs, everything crammed to the border which is also just noise as it doesn’t really separate the posts from one another. You cannot tell if the header isn’t a footer of the previous entry. Whitespace is a much better separator than lines/rectangles. And vertical logo? Yuck.
Feed banning may not be as convenient on planet gnome, but you can sure read it much more easily and it’s a pleasant view at that.