The RD has a special place in my heart and I really dig the shape. But weight and phat neck (not that I mind) as well as an unconventional look worked against its acceptance from day one. I started learning bass in 1977, the year the RDs came out. I was immediately taken by their look though they were totally out of my budget. But I longed for one. They even caused a little bit of a splash when they were first released, there was some initial interest. But woe did that die down fast. Within a few months, the Mafia of Fender Jazz (Jaco!) and Fender P players that held German bassdom in an iron grip only referred to the RDs as "tree trunks" and "boat anchors". Instead, the new - and incidentally also active - bass on the market you should look out for became the Stingray - that found favor due to its Leo Fender ties. It was very much an elitist thing, if you were to be deemed "serious" about your instrument, you had to play a Jazz, a P or a Stingray, nothing else. An Alembic would have been tolerated too, but nobody could afford one.
If a few name players had adopted the RD as their mainstay bass in the late 70ies/early 80ies (just imagine Jaco P or Stanley C picking one up and recording as well as gigging with it), things might have been different, but from my perspective the bass was doomed by 1978. A decade later, Novoselic only resurrected something that by then had been relegated to a pawn shop image.
And of course there is the weight test. Anybody picking up a TBird for the first time invariably always exclaims: "Wow, it's a lot lighter than it looks!" And anybody lugging an RD will always say: "Yup, heavy, just like I thought."