so let me see if I understand this, you were a new or occasional seller on eBay who took up the generous offer of free listings, given by eBay to encourage more full time sellers to the site.

you were successful... very successful, sold so much you qualified for their p/seller level... well done, you must be doing something right, you list AND sell... great!!  eBay must be a good venue to sell on, as you have made great sales since the introduction of this special offer... well done you and well done eBay.

now eBay are asking you to join the ranks of their regular sellers, of which we are millions, and pay fees, like the millions of regular sellers do, ok, understandable, you are using their service, you tried their free offer and found out it is certainly something you can do well, so now you have to pay

it is not a matter of eBay''gave'' you Powerseller status, YOU reached that status by selling well.
the only way to ''opt out'' of being a powerseller is to sell less, which surely defeats the purpose of listing on eBay.

sure free listings are GREAT, if you dont want to sell anything at all, just list, for free, then you can do that for years..... however, if you want to SELL, then you have to acknowledge that at some stage you will reach a level no longer considered 'casual seller' and start paying for your listings, which is OK cause it means you are eBaying well, have good products and selling them !