You should care about formatting your posts to the point where they are easily legible by everyone, but for a different reason: it will make it easier for you to get answers, and it will improve the quality of the answers you do get. Why? because every second that a potential answerer spends being annoyed by poor formatting is one less second of them thinking about the physics, and one second closer to them deciding to simply leave the post aside and going to find another one. Having a question that is correctly formatted, easy to read, and which clearly conveys the heart of the question, is the number one fix to getting better answers.
If a question is formatted so badly that it takes a lot of effort to even begin to understand what it's saying, then some people can and do get annoyed enough that they'll downvote before leaving. This is allowed for the same reasons that there is no requirement for anyone to explain their posts, because it promotes uninhibited voting based on the usefulness of the question, and it helps clear, interesting, useful questions float to the top. A question with terrible formatting is less clear and less useful, so it is right that it does not get to the top.
That said, if the post has minor formatting problems, a lot of times the response is simply for users to jump in and help with the formatting to help the 'real' question shine better; the cases where this doesn't happen are often because the post is so muddled that we can't even tell what the user means to ask in the first place. Want to see some examples? Take our recent prolific editors and see their recent edits (profile > activity > all actions > revisions). You'll find a lot of people jumping at posts that have issues and fixing them instead of downvoting them.
In your specific case, there are two very clear things you can do that will make your posts more readable by a very wide margin:
Adding a space after every punctuation. In English, all forms of punctuation used in text (. , ! ? ) : ;
) are directly followed by whitespace. Skipping that whitespace (as in e.g.skipping the whitespace,like this) is visually very jarring, stops the visual flow, and takes attention away from your message.
Correct use of paragraph breaks. Paragraphs need to be of an appropriate length (roughly two to four sentences) and they need to be separated by a blank line in the source text to display correctly. Skipping this blank line produces paragraphs which are joined together (either as a single paragraph or as two immediately contiguous ones) which produce a 'wall of text' that's very hard to digest.
As an example of how this looks like when it is done incorrectly, consider the following text:
This is some sample text to display how wrong paragraphing can look wrong
and detract from your answer, and how the fix is actually very simple.
This is some sample text to display how wrong paragraphing can look wrong
and detract from your answer, and how the fix is actually very simple.
which renders as
This is some sample text to display how wrong paragraphing can look wrong and detract from your answer, and how the fix is actually very simple.
This is some sample text to display how wrong paragraphing can look wrong and detract from your answer, and how the fix is actually very simple.
Note that there are three white spaces after the end of the first paragraph, which cause the joined-but-malformed paragraphs. Instead, you need to introduce a blank line between paragraphs,
This is some sample text to display how wrong paragraphing can look wrong
and detract from your answer, and how the fix is actually very simple.
This is some sample text to display how wrong paragraphing can look wrong
and detract from your answer, and how the fix is actually very simple.
which renders as
This is some sample text to display how wrong paragraphing can look wrong and detract from your answer, and how the fix is actually very simple.
This is some sample text to display how wrong paragraphing can look wrong and detract from your answer, and how the fix is actually very simple.
and this is miles easier to read for most English speakers, particularly with longer paragraphs.
Both are easy to implement and they will visibly improve the quality of your posts; all you need is discipline in implementing them consistently. This might take some effort, but you need to accept that we all spend effort here to produce the best-crafted questions and answers that we can, and you need to match the effort you put into your questions to the effort you expect answerers to spend on their responses, both in terms of content and in terms of formatting and readability.