It can be, if you expect that the code you're reusing will often have defects that will cause defects in your application, and therefore have to be fixed. (Of course, you should thoroughly test the part of the library that you actually used and verify that it does the job correctly before you ship it with your product, but we all know the world isn't that tidy.) If this is the case you should not make commercial success dependent on third-party libraries where you are not sure about support - whether open-source or not!
But bear in mind that "few updates" and "likely to have defects" is not necessarily correlated. In fact, it may be anti-correlated for very wide-spread, very mature products. And of course, the bonus of open source is that if there is a defect with a clear and obvious fix, you can just make the fix without having to wait for external support at all.