Solo doesn't mean much in a game that was built around partying from the ground up.
Immense popularity because the job was a gravy train to 75 and merit groups, specially after TAU hit and people decided to kick WHM to the curb and use RDM as a healer with a bard as puller. It was literally the closest thing you could get to a princess job without dealing with the crappy leveling on BRD up until you got Ballad and March. It was also the one of only two ways for anyone with an MP bar to recover MP because the devs were too lazy to make it inherent to all classes with an MP bar. In short, the reason people wanted RDM so much was because they were desperate for anyone with cures (see: SMN/WHM) and because mages were addicted to Refresh and Ballad as if it were crack. That's called inflating the value of a job through a gimmick. A bad one a that. It's what is known as bad design.Also, BST was alienated because people were stupid and didn't understand how the EXP penalty worked, not because the job itself was misunderstood. RDM is hardly in the same boat, it`s gone through phases of IMMENSE popularity in this game, and it hardly suffered from a stigma such as the EXP pentaly.