'I think that mixed in with the totally pointless changes like rounding box edges there are others that help ebay achieve its insatiable appetite for data on everyone who uses the site.' 

Yes. When the penny drops that pretty much every change/update/tweak etc is more for eBay's benefit - one way or another - than about providing any genuine improvement for those using the site, it makes you feel increasingly reluctant to continue to be a part of it. 

Unfortunately, unless you can manage without doing anything online, it is difficult to completely avoid all this modern day nosey-parkering...