It's been a while since I had contact with teachers and computers.
Our company bought its first computer (Commodore 8032 used for counting money...spreadsheets). Except for one-of's here and there, computers were not in classrooms.
I occasionally traveled to another province where the brother of a fellow employee had a job to investigate what was available for use in education. He was a teacher prior to landing this plum job. When I was in town, I looked him up, had dinner, visited his friends, etc. They were all very knowledgeable about computers. They were writing instructions/ideas , many were messing with BASIC, etc.
They were all teachers... real teachers with home rooms who marked papers at night and they were all learning on their own and from each other. That group of sort-of randomly group of a dozen or so folks was quite likely the best "amateur" computer experts in the province.
Where I currently work we have a help desk that treats or escalates calls from "Fonts are wrong in Word", "Can't log in.", to calls requiring senior IT folks with meetings and conversations in hallways. Our customers vary from three person family operations to national accounts with multiple small and large offices. For most of these we provide first level support. "Fonts, email bounced, I lost a file, etc.
If your business is not computers. (oil, pizza, educated children, etc.) then you have to provide first level support to the folks who work in that business. It's expensive per user and it's a cost that's easy to hide by requiring users to do it themselves or sleeze it from someone whose job is to do something else.
A few years ago we quoted on a hardware software job for a group of schools. (we weren't chosen)The quote was for supplying hardware, installing software and standard warranty on the job. No costs were allocated for support.
If you want workers to produce something and work with computers, and use them to count money or pour concrete, you have to support the dumbasses, smart ass know it all's and klutzes.
I think it is reasonable to have most teachers trained to the level of a "user" with first level support for "Getting an error when opening Word"
It doesn't matter whether the operating system is Microsoft Linux, PICK, or what applications are used. If you expect folks to use computers to do their job, you have to provide ongoing support.
I've seen many schools with computer labs with more than half the equipment not working and teachers with computers on their desks that aren't being used because of a problem
Teachers are no different than any other trade around computers. Office clerks, engineers, lawyers, executives, shpppers... they all contain a subset of people who are horribly clueless and dangerous with a computer.
It seems that people expect teachers to be better with computers than a typical tradesman in another industry.
I think it is possible for a middle aged teacher with very low computer skills to teach an elementary class programming if they are provided with the tools and support. A teacher who has two servers at home and writes software for Linux in his spare time might... might be able to do it better.
I'd have a hard time deciding the weight of "Good Teacher" against the weight of "Good at the subject being taught"