I don't find ASM as difficult to debug as HLL
That was one of my arguments ages ago. It takes some time to get the tricks of C debugging (beyond basic). Also, in C debugging, sometimes, when being at a loss, debugging the disassembly ("debugging beyond basic" will lead to the "aha".

and I don't find ASM as difficult to design as HLL.
what is the diufference between designing with C directives and designing with ASM MACROS? I find designing waaaaaaay easier with C than asm

However, I have doubts as to whether extensive maintenance, beyond a few minor tweaks, is often necessary
True for amall dumb apps where asm will do quite well, not true for the larger apps, I babyed a product throgh 12 instances of "feature creep"

I'm of the opinion that a newbie who wants to start with a "small" MCU has a really hard row to hoe.
first mistake, why use a small as your first?

I don't maintain that ASM coupled with ULTRAMON51 is the only or even the best way to do production work, but it's a very straightforward way to develop hobby projects, and it doesn't cost a semester's tuition.
neither does a SILabs toolstick ($12 if I recall)

I doubt Andy or Erik would have easily succeeded plowing up new ground with HLL if they hadn't already possessed a firm knowledge of the 805x core
the same is true for "plowing up new ground with asm"

Erik