You can add another point to the data set. Granted, I don't crash my browser looking for coupon codes, but I always try to, when I see a check out page like this.
The other issue to me is that everything else on that page is required except the coupon code. It really makes me feel like I'm missing something.
Remember, this is the World Wide Web, so any claim you make is a gross over-generalization because, by and large, you don't know who your customers are going to be. You can only do A/B testing, collect feedback from your customers, etc, to slowly get better as you go along. If the author is in the minority, who cares? If not, we'll start to see different types of check out pages and the ones that will "win out" will be the ones that meet a sweet spot between ease of implementation and effectiveness.
The other issue to me is that everything else on that page is required except the coupon code. It really makes me feel like I'm missing something.
Remember, this is the World Wide Web, so any claim you make is a gross over-generalization because, by and large, you don't know who your customers are going to be. You can only do A/B testing, collect feedback from your customers, etc, to slowly get better as you go along. If the author is in the minority, who cares? If not, we'll start to see different types of check out pages and the ones that will "win out" will be the ones that meet a sweet spot between ease of implementation and effectiveness.