Beyond what Walter said, your question may have a very ambiguous title. Like "Please help me". Nobody knows whether to bother looking, and for such an ambiguous title, they expect your problem will be a newbie one.
Or it may be clearly one where people know that you are confused as hell about what you are doing, just from reading the title. I avoid questions like that, because even if an answer exists, they always turn into long involved consulting problems, where multiple, unrelated questions get asked. And such a problem always seems to drift, because the person did not ask the real question they had in the first place.
Or it may simply be that you asked questions in the middle of the night, when most people who might have an answer were sound asleep. Or you asked questions on a weekend, or some major holiday when people have something better to do.
It may be that your question, while possibly well posed, is clearly one that only a very few people on this forum are able or interested in answering. It may be a problem that clearly is not even about MATLAB, in which case you should be posting your question on a forum where it would be on-topic. That greatly improves the odds of finding a match between problem and a potential solver.
Questions that are 3 years old are generally dead questions. And most of your questions date to 2015. Even if someone had the answer to a 3 year old untouched question, most of the time, the person asking it is no longer interested in the answer. So there is little reason for resurrecting a question into the walking dead.
Much of this will have been covered in this question itself: