how can you call them that when you are not allowed to install your own software on those devices? Calling them computers is something I refuse and I suppose hacker news people understand why.
At work, I'm not allowed to install arbitrary software as well - but policy doesn't make my workstation any less of a computer. Also, not all smartphone vendors are as anal as Apple, and there are always workarounds [1],[2].
I don't think we actually disagree - it's just a matter of definition; please note that I intentionally didn't say (personal) computer, but (general-purpose) computing device.
I would draw the line at what the device's technical capabilities are, not what I am "permitted" to do.
If you use permission in your definition then it becomes impossible, by definition, to restrict the use of a computer. If Dell's next cheap desktop was locked down like Apple locks their devices down, would you buy "Well it's not a computer you know, since you are not allowed to run what you want on it."? No, of course you wouldn't.