I think what GP is implying is that it's a self-fulfilling prophecy: VCs are biased against solo founders because historically and culturally they've been overlooked/undersupported by VCs.
Indeed, and I am highlighting that the actionable take-away for someone considering founding a vc-backed startup solo is: don't. You're fighting uphill enough, no need to make it tougher.
Except that there is no objective evidence that being a solo founder is harder.