Charging excessive P&P was only scamming ebay, not the customer.
Surely nobody was so dumb as to fail to notice a £10 P&P charge on, say, a £1 USB stick and think they were getting it for a quid? However that £10 wasn't subject to ebay fees so it was just another way of sellers avoiding paying ebay fees. Obviously ebay didn't like this, and that's fair enough. If an item's retail value is, say, £10 and would cost £1 to post some sellers were putting the item up at £1 and charging £10 P&P. Most buyers were happy with this arrangement and were therefore complicit in this avoidance of fees.
I don't think, however, that imposing free P&P was fair. Ebay had in effect discovered a way of charging fees on P&P which isn't part of the deal that most sellers signed up for.
An upper limit on P&P seems a fair compromise. So (for once) fair play to both sides for coming to an arrangement that seems to satisfy the majority - because you're never going to satisfy everybody.
I hardly buy from ebay these days except for used stuff. While the asking price often looks cheap it will often come with a fairly hefty P&P charge that makes it more expensive than many of the big shops that don't charge P&P.