I have been following the replies and think there is good selection of views and some very valid arguments.
So a few points:
1) I try and think of the Type 022 as the first of a new class rather than just a new type. I will not be surprised to see a rather beefier design for blue water operations in the not too distant future.
2) The main thrust of my OP was specifically for direct ship to ship engagement, and that either this is now highly unlikely and will be undertaken by aircraft, subs or FAC's. The role of mid size ships in other defensive roles is not under question although a change in form as a consequence of a change of role would be likely.
3) People have mentioned cost and I would have to counter with survivability. A number of mother ships would provide good value for money in my opinion. FAC's are not Aircraft and do not need to "land" every few hours. The boats could be on patrol for days at a time, refuel at sea and can rotate crews etc, only needing to dock for maintenace or long distance transit.
4) There are few examples of AShM being used in real combat, but these make sober reading. The main example has to be HMS Sheffield in the Falklands. Most attacks were by Dumb Bombs and many ships that were hit, still managed to survive; just as their WW2 predecessors did, coming home looking like old Prize Fighters! Sheffield was different though and one Exocet fired by a third rate, developing world nations airforce, sank a state of the art destroyer of one of the worlds greatest Navies when it was on full alert in wartime conditions.
Beyond that I also see the FAC having a greater role, based on some other developments which I think are likely in the coming decades. Principally, I suspect that we will see a move away from the kind of Carriers and other large support ships we see now, towards much larger facilites, which are moveable, rather than necessarily mobile and which combine with elements of Oil Rig construction to build large semi-permanent structures in International Waters - effectively artificial Islands on which full bases can be operated. This again would limit the need and scope for Destroyer sized ships and much bigger facilites can be built on base etc. It also seems a far more effective way of projecting power abroad than the current CVBG.