[onion2k]

At a company I worked at engineering used to go on customer visits, but the "customers" were the executives and managers who make buying decisions and put forth requirements.

Developers should meet the customer organisation to talk to users. If you're not talking to users you're not getting the most useful feedback.

Where I work we often supply software to other software companies, and our UX team goes and visits their customers to get insights about how our products are used.