Why did that put you off? This is a very common thing for reviewers to do. It is useful for you, because it makes you aware of other people who work in the sa

Why did that put you off? This is a very common thing for reviewers to do. It is useful for you, because it makes you aware of other people who work in the same problem as you, leading to future job prospects, etc. But more importantly, it is useful for the readers of the article! The alternative is several independent communities of researchers that work separately on the same problem, but do not acknowledge the existence of each other. Now, that would put you off!