It's both. If pro cameras (or even point and shoot) had really bad software, we would see corrupted files all the time, unreadable media, exposure completely off, weird bugs in battery monitoring or power consumption, etc.

Smartphones have constant "updates" and yearly new OSes, and we think it's marvelous if a two year old phone still functions. Yet digital cameras from 15 years ago still work fine with exactly zero update.

Robustness and dependability are important features. In-the-box HDR is cute but it matters less.