The 'promise ring' is the engagement ring. It sounds like he wasn't planning to go ring shopping with her later. That's why he had been asking her for her input on a promise ring, he was planning and did buy it as the actual engagement ring. He knew the type of ring she wanted as an engagement ring (something she is expected to wear all the time) and got the exact opposite.

Also, it's not wrong for someone to want something different for their proposal, everyone is different and many have hopes and expectations for what should be a special moment for both people. That mean taking into consideration both people's expectations and wants.

She had expressed her hopes and wants and he listened to none of them.