HP-25 purpose

[BobVA]

(11-03-2020 01:04 AM)Matt Agajanian Wrote:  Lacking looping...

The lack of special loop instructions (e.g. ISG) was a little inconvenient, but the HP-25's direct register arithmetic made the use of conditionals for looping not too much of a bother.

I'd speculate that the above noted ROM constraints, the small program memory and lack of program storage all tilted the balance of features towards math functions vs. programming features.

Along the lines Thomas noted, I'd always thought the programmabilty was designed mostly for on-the-fly automation of repetitive calculations, much like the HP-55. It's perfect for the kind of short programs you could create directly from the keyboard, perhaps without even first writing them down.
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That was pretty much how I used mine in college, despite having a tiny notebook of programs stuffed in the case with it.