Why are the HP Prime and HP-35s so unpopular?

[Benjer]

When my engineering classes were still in person, it didn't seem like anyone was using HP calculators. The calculator policy for the college of engineering here is pretty straightforward; it's just a link to the NCEES calculator policy page.

During one of my structural analysis exams, the professor was checking everyone's calculators to make sure they complied with the policy. When he saw my HP 35s, he remarked it was the first time he had seen it, although he did know of them. Everyone else is using Casios or TIs.

I have to wonder if cost isn't a factor. a new HP 35s is >$50, while the other models can all be had for <$20.

When it came time for me to study for my FE exam, I ultimately switched to a Casio myself after test driving the HP 35s and a TI-36x Pro for it. It just seemed like the better machine for the job.