The spoj tag appears to be a meta tag much in the same way that homework was - it indicates where the problem came from but does not seem to aide in searching or tagging. It seems to be much the same as an excuse for poor "fix my codez" questions (that in many cases are left without other useful tags).
Should this tag be destroyed much in the same way that homework was?
Consider from Death of Meta Tags
The reason meta-tags are a problem is that they do not describe the content of the question. They describe some other aspect of the question, like the author’s skill level, or the author’s motivation for asking it, or generally what “kind” of question it is (poll, how-to, etc.).
How can you tell you’re using a meta-tag? It’s easier than you might think
If the tag can’t work as the only tag on a question, it’s probably a meta-tag. Every tag you use should be able to work, more or less, as the only tag on a question. Meta-tags, like [beginner], [subjective], and [best-practices], are useless by themselves — they tell you nothing at all about the content of the question.
spoj tells you that it is a programming problem, but then nearly every question on SO is a programming problem.