We needed to win contracts, so we needed to tick their checkboxes, but we also cared for the user experience (good UX was almost never a strict requirement from our customer).
Our competitors' software was very painful to use, so we wanted to differentiate in this regard.
This made our own lives easier as the training was easier, the users we interacted with (that usually had no say in whether our solution was bought to them or our competitors') were happier and recommended to their managers (where they could) buying more stuff from us.
In the end this was 80% driven by pride (our software doesn't suck) and empathy (I couldn't stand using the software if it was as bad as our competitors') but to some extent this was also in our interest (especially in the long term, where your brand is built).