What does voting down mean? Should I have a bad feeling when being voted down? Did I do anything wrong? Should I desire the favor of the community? This is not science. Science is not democratic. If you want to do science, at least justify yourself. I'm not here to be voted down by you, stupid a--h---. You can't solve my problem and vote me down. You think I like your site so much. Go to hell. I will stop visiting this site, as this is not science. I'll leave you a message here because of good civility. Repent! The kingdom of God is near.
Zirui, cstheory is a Q&A site with a scope defined in its FAQ. The scope of cstheory is research-level. Questions that are at the level of difficulty of typical undergraduate students are not part of the scope. There are other Q&A sites which have a more general scope like Math.SE that would welcome questions from students.
Votes (down and up) are one of the main ways users express their opinion about the quality of a question and how interesting it is. A user may down vote a question if she/he thinks the question is off-topic or has other problems (e.g. unclear, not answerable in its current form, argumentative, not a real question, post to solicit opinion, ...).
If you want to know why your question is down voted you can ask for that in place of attacking other users. I will explain my down vote in more detail below:
It seems to me that you are trying to find a way to get around the undecidability of halting problem. The halting problem (as it is defined in the literature) is undecidable and that is a mathematical theorem. Now one might be interested in decidable variations of halting problem. That is a well studied topic, and one can ask a research level question about that. There are also researchers working on these kind of problems who try to find ways to deal with undecidability in practice (mainly in formal methods community, but also in theoretical computer science).
On the other hand your question has no sign that you are familiar with the literature. I can tell that this is something a typical undergraduate student taking their first course in computability would ask. It is nice that a student would think about this kind of problems. But everything has a place and the place of this question is not cstheory. If you ask it on Math.SE you probably will not get any down votes.
As an analogy, it is completely fine and even encouraged that students ask questions like this in an undergraduate computability class from the instructor. Asking it in a research-level computability workshop will probably be unwelcome.
If you ask a question about halting problem and show that you are familiar with the literature and understand the basics in the area, and the question is a real question (posting a question to see how others think about your idea about how to solve halting problem is not a real question) and is clearly stated (can be answered without much back-and-forth comments where others try to guess what you want to ask, which can be a sign that the question is not well-thought), then that can be on-topic and I would guess would not receive any down votes.
ps: I would suggest that you take a look at the this section of the FAQ and also the pages linked there. Following those suggestions would increase the chance that your questions are well perceived by the community.