Not surprising, since Venture Capitalists like to invest with other Venture Capitalists. There are a number of ways to contact the Venture Capitalist that are effective. One of the most common generalities entrepreneurs are sometimes told is that the only way to get through to the Venture Capitalist is by using a referral. This does not seem to be the case.
Direct contact is fine, according to a significant number of VCs.
So if you have can get a referral, great, but don't think you have to have one, to be taken seriously by a venture capitalists.