Reviewers in spite ?

I received a review for my paper like a week ago. The decision was a revision. I don't mind revisions as long as they are reasonable but there was something strange about how the editors and reviewers acted. So let me start by giving a brief intro.

Let calls an old problem P (very useful for variety of applications); another related problem called RP. 

NS= novel solution by me and my collaborators ; NSRP= novel solution for RP (has got nothing to do with me or my collaborators)

Now, we got 4 reviews; two reviews were favorable and one of them was extremely detailed.

two reviews were not so favorable. Here's the funny part;. the two reviews that were not favorable assumed that the problem being discussed in the paper was RP and a solution linked to NSRP is being presented. 

Then I asked myself, was the story told well? were we not clear enough? I wouldn't comment on how good story was but I can claim at least this: We made explicitly clear that the proposed solution had nothing to with RP. 

If the reviewers didn't like the story, or the writing was not up to the standards they could have criticized it, right? Instead what we got was half broken reviews telling us that the solution to the NSRP has been presented by blah blah and the contribution that we are presenting is trivial. I am willing to get criticized for not presenting a more contributing manuscript but at least criticize me for what I am saying, not what you think I am saying !

More over we got the reviews after 8 months! yes you read it right..after 8 months and that also by repeatedly requesting the editor(s). Leaving aside all the questions about the manuscript I have to ask this: Is it possible that the two reviewers did this in spite just to delay the publication? FSP notes that apparently the editor can sink a manuscript ? would there also be reviewers that would give spiteful and non-constructive reviews just because they might be one of your competitors trying to solve the same problem?