The Help Center says: "You should only ask practical, answerable questions based on actual problems that you face. Chatty, open-ended questions diminish the usefulness of our site and push other questions off the front page."
Putting a soft-question tag on a question doesn't change this.
You give the link to some recent soft-question tagged questions. And some of these are actually nice questions without a downvote. For example, this question, is in my opinion a good question. It does not admit a definitive answer and so the soft-question tag is appropriate.
With an example like this one, I don't think the question in on-topic because the answers will depend heavily on opinion.
Looking through the list I also see several questions that are off-topic, like this one.
I wonder if the reason that soft-questions are more often downvoted is that it is a tag that is often used of these open-ended chatty questions.
But maybe someone could do some statistics so we could see if it actually is the case that open (i.e not closed) soft-question tagged questions are more often downvoted.
Also, could you provide some (several) examples where you believe a soft-question tagged question was wrongly downvoted?