Before I start, let's get something out of the way:
So long as they have the appropriate privilege, a user can downvote a post for whatever reason.1
Though you haven't explicitly stated all of them, I am going to address a few of what I presume are your concerns:2
What is Super User supposed to be about?
I asked if something was possible and my ...
To answer the implied question of "why?" when you say:
And now I cant ask a serious question!
You have what is known colloquially as "history". Specifically you have a history of asking bad or off-topic questions.
You have asked, in total, 10 questions on this site. 5 of those questions were closed, deleted and/or downvoted. For your information those ...
This is just an example of why you may be getting downvotes, mainly to illustrate why "not useful", "unclear" and so on can depend on your perspective.
While you may consider the question useful, many other would consider the topic of installing an unsupported and effectively end-of-life operating system on hardware that has explicitly dropped support for ...