Pretty disingenuous to frame it this way considering that 21 states, DC, Puerto Rico, and other US territories didn't vote until after Bernie dropped out on April 8. Before then, the popular vote totals were extremely close between him and Biden. Bernie also won going away in many states, including California. It's not accurate to say "only one in four primary voters wanted him to win." You can tally the popular votes before April 8 and see that it was more like 35-30 Biden-Bernie, with the plurality in favor of Biden.
(So yeah, while technically accurate, this type of revisionist framing just feeds into any ongoing resentment. Not productive, no need to open old wounds – and I'd say the same to Bernie.)