It's made a dual intent because it's impossible to prove the lack of immigration intent for any long-term visa. It's not the only dual intent visa, almost every long-term non-immigrant visa is dual-intent for this reason. Even the TN, which is not proclaimed a dual intent is such de facto since the TN visitors don't have to prove the lack of immigrant intent either. The reason TN is such an exception is that it's not issued by the DoS and the concept of "dual intent" exists only as a legal fiction around the DoS procedures.