Plenty of counterfeit goods are sold on Amazon. Unless there is the potential for lawsuits (like this case) they don't care.
Business steps Amazon has taken in the last few years have encouraged and increased the sales of counterfeit goods.
This is why I avoid purchasing from Amazon. I buy goods right from the manufacturer or a dealer not known to sell counterfeits. Amazon is not a reputable seller in my opinion.
I disagree with both your assessment that Amazon is not a reliable seller and that they encourage the sale of counterfeit items.
I am an Amazon Marketplace seller (mostly toys, not optics or astronomy items) and they are pretty strict, and frequently suspend sellers who don't know what the infraction is and require them to submit a plan of action to get reinstated. Even when sellers know, it is based on a bogus complaint.
I sold some Hexbugs, one to a Norwegian who had it shipped to OR and used a freight forwarder to ship it to his country (These I had bought on clearance at Target, which some might disapprove of, but it is not any different than say Tuesday Morning, Big Lots! or TJ Maxx buying up salvaged inventory from retailers and selling in their stores) and when the buyer complained the battery had leaked and it appeared to him to be counterfeit and I refunded him, rather than making him send the item from NO to US, they blocked me from selling Hexbugs (fortunately I didn't have too many left).
Another time, someone complained about a Monster High item that it was not legit and they blocked most of our Mattel items until we sent copies of invoices. They are frequently particular, requiring invoices (not cash register receipts) within the last 180 days. Some of my items are from a Mattel-owned outlet store and come with cash register receipts, but that doesn't work. Others I acquired more than 180 days ago.
I also can't sell Disney Frozen items purchased directly from Mattel because of this reason (approval requires an invoice not cash register receipt) (*Note, as of March 31, 2016, Mattel not longer sells Disney Frozen of Disney Princess items but these were purchased before that.)
They also are strict about DVDs (which I don't sell a lot of) and certain electronic brands, like Sony and Canon, who have apparently persuaded them to not allow unauthorized vendors from selling their products in 'New' condition.
One other data point, I had purchased from Amazon a Spider-man toy, attempted to send it to their warehouse, which they did not allow as a 'hazardous' item because it contains an aerosol silly-string like propellant. They did let me sell and ship directly for a while until they removed that listing, told me it had been recalled a certain date (one month before the date of my purchase from them) and I checked CPSC and Hasbro website, neither had a recall notice and tried for weeks to persuade them they were mistaken about it having been recalled and just when it looked like they were going to let me, they said it wouldn't happen. No one was willing to take that risk.