Modern missiles gain the increase in range with "lofting", and ramjets are generally inferior in this aspect.
Top speed is a desirable quality against capable fighters, especially more so in a VLO vs VLO scenario. Ramjet missiles are limited to Mach 4.
High-speed missiles can be both lighter, cheaper and longer-ranged with rocket engines. It's not possible to achieve high ballistic trajectories with ramjets. The advantage of ramjets is being able to fly at low altitudes for a long time.
Maintaining speed and relative velocity after the engine shut-down are also important. A Mach 3 ramjet missile would be advantageous against an approaching aircraft, while a Mach 5 rocket could be more advantageous against a retreating one. Time to target is critical and ramjets bleed energy much faster once they burn out.