You are spot on and lots of people forget it's also putting one's reputation on line. Imagine you pass on this and that piece of information from a wiki page (which changes how the wind blows), only that to be found defective.
Ok, I guess universities and providers of professional trainings operate differently then. I'm quite sure my unviversity teachers never really cared about whether their professional reputation was put to risc by not using anything official since they didn't even used any official slides or logos at all most of the time. Except maybe on the first slide, which explained that e.g. Java was first developed by Sun and is now owned by Oracle. The only official logos I saw in every damn lecture were the logos of the university and their institutes. Another explaination might be a cultural difference between Germany (where I live) and other parts of the world.
Consider one more thing, Proxmox are a rather boutique company, if they started to become very popular, a big player will offer something that the majority shareholder would not be able to reject and there goes your "alternative", so maybe everyone here should be happy they are not punching above their weight, in this sense.
That Proxmox would benefit in the long term from a "education tier" is a no brainer I agress. But as far I know right now they are busy enough in dealing with the new demand of potential customers and partners due to the Broadcom situation.
And for professional training providers they have their partner program. I can unterstand that they hesitate to share their material for partners with non-partnered institutions.
Concerning the ticket you brought up: As far as I can oversee there was a quick reaction by the developers who discussed the issue and thought about potential solutions. I can understand that you are not satisfied with this result but "We don't think this is a problem in the real world" is different from not reacting (which was the way your description here was phrased). How is this different to other vendors who declare a customers wish "out of scope/won't fix" etc?
Last edited: