/u/penaltyornot is right.

See my other comment. For people who can call themselves a marketer, in just about every niche, this new agreement is better. It's basic maths.

It's people with your mentality that let a multi-billion dollar company like Amazon get away by shaving off the % of commissions every single time.

Ha. He certainly isn't. If you are driving targetted traffic, this new agreement is better. If anything, I believe Amazon is being too generous given their ability to push this harder.

No, it doesn't make sense, when I (and many others) started driving traffic to Amazon, we did it because we were incentivized from certain policies we all agreed in a legally binding contract with Amazon, one of which was the commissions extended to the other items in the cart.

This is the same legally binding contract that says:

We reserve the right to modify any of the terms and conditions contained in this Agreement at any time and in our sole discretion by posting a change notice, revised Agreement, or revised Program Policy on the Associates Site or by sending notice of such modification to you by email to the primary email address then-currently associated with your Associates account.

There has been a variation of this in every contract going back the last ten years (I print them off and save them, checked the first one)

You agreed to this. It's how contracts work. No one forced you into this.

At the end of the day, Amazon is buy one affiliate offer provider in a sea of many. I have never earned more from amazon than from other affiliates. If you are a beginner, then amazon is the easy choice. If you have been doing this for years then amazon is the lazy choice. If you have established, targetted traffic, you are leaving money on the table by using amazon.