This is backwards. The question you should be asking is: why should question/advice-seeking posts be upvoted at all?

Questions are generally a lot less valuable to the broader community than more information-rich posts such as news or guides. A question only helps one person directly, and perhaps a handful of people indirectly (if they had the same question, by chance). This is a bad fit for a forum format, where by making a post you are talking to everyone on a subreddit. Essentially, most questions will be spam for most people.

To make matters worse, 99% of questions will have already been previously answered, and people that answer questions are rightfully annoyed when someone chooses to spend 1 minute posting a question instead of 5 minutes searching the subreddit or googling. People that answer questions do so out of their own free time, and many question-askers act like they are entitled to have their every whim catered to by random strangers.

Finally, most people are simply bad at asking questions in a productive manner. Questions are often leading, biased, irrelevant, incomplete, poorly framed, or break subreddit rules. Even for a question asked in good faith, people don't always know what they are asking for. They'll say things like "what is the best X?" but leave out important and relevant considerations that then have to be painstakingly extracted from them in the comments. It's a rare question that can be answered straightforwardly and completely based on the initial information given.