It's probably more about cost savings than anything else. Why add a USB port and the associated functionality required to do manual updates when it's got a fantastic remote update capability?
To be fair, if we're talking about cost savings, it would be a lot cheaper if they didn't bother with paying devs to push firmware updates to a fucking microwave that should just work on it's own.
It doesn't need extra hardware. Most routers have some rudimentary TFTP boot mode that can be accessed by powering it up while holding a certain button. The device already has Wi-Fi, so the same mechanism can be used - if powered up in recovery mode, it'll scan for a specific SSID and then TFTP boot from a specific IP on there.
Eh, I think you're being uncharitable. My 80 year old mother could definitely figure out how to hold down a button while turning the thing off and on. We've been living with some version of that reality for decades.
I wonder if that percentage of tech-savvy "elderly" is going up over time. I know I remember hearing that about anything computer related 20 years ago, but many of the people in the upper age ranges now lived with computers for a majority of their life.
My grandma is not tech savvy, but can follow directions pretty well. My spouse's grandma is tech savvy to a certain level and manages her own computer and photo library. I know either of them would likely be able to hold down a button and follow some set of directions to join a wifi and upload a file.
25 years ago, we were all bitching about having to program our parents' VCR for them. In 25 more years we'll be asking a teenager how to get TikTok beamed directly into our brains like they're doing.
My mom is pretty adept with her iPad. If she was instructed to download an app, load it, and then stand in the kitchen after doing the button-push on the microwave, it would be completely within her ability. She knows what a wifi network is, she knows the password for hers. She is definitely slowing down a bit with age, but she rarely requires me to come over and help her with such things, at most she just asks for more confirmation these days before she says yes to a prompt.
That last part could also be because I harp on it every time the topic comes up, that under no circumstances should she be answering yes or ok to any random prompts that she isn't very familiar with already, and please call me if she's at all questioning the legitimacy of what she sees.
If it has a companion app for a phone (which this appears to be), you could easily have the phone do this for you. Not unlike setting up a wifi hotspot.
Just have support walk them through a menu on their phone for an "advanced" feature they just tap on, then hold the button on the microwave. Voila!
(Granted, I did tech support long enough to know this isn't easy; if someone can follow instructions, however, it should be doable.)
So is the percentage of router users... and yet those debug modes are there because they cost nothing and can be useful in "oh shit" moments like these.
As a consumer I want a button which I can press for 10 seconds to reset the device to how it came out of the box. That should include any firmware updates because remote bricking happens all the time.