The problem can be roughly summarized on the pic below. To go to normal A2A range (i.e. either OFCA or outer air battle) with VLRAAM capability, SHornet takes an incredible balancing act, and gets down to Korean war era specs(even normal OFCA for this platform is barely supersonic, and is always at disadvantage). Which, in turn, forces one hell of a missile to compensate.
But there's more than that. For example, Hornets only get passive targeting capability through combined drop tank

od. Which isn't just undroppable (you drop it - you buy it for the rest of your life), it's a big, subsonic tank.
Yes, superhornet is really a king of low speed maneuver, better than flankers. And i am running from thread to thread preaching that it's very important nowadays, because of drone hunting. But it isn't very relevant for normal a2a combat.
Note that comparable F-14 carried for VLRAAMs, and its profile included both significant supersonic dash,
and allowed to cross M=2 while at it.
And Shornet...in too many ways, its BVR performance is not unlike of a huge AV-8B+.
