Proof by contradiction. Mixxx (http://mixxx.org) has probably 2-5 active developers and we've received 3 or 4 students every year since the beginning of the SOC. I've been to the GSoC mentor summit as well and there are plenty of small sized projects. In fact, this year they focused on accepting more smaller projects via the 'referral' system whereby projects could refer other small projects that would be a good fit for the SOC.