My two penneth, I stopped posting on here shortly after getting my Cortina mk5 - although it was 'osf' , it didnt seem to fit in so well as it was too much like the newer fords . So I went over to 'Cortina80' for a while.
Then I got my XR3 and now use the mk3 Escort forums, cos I'd rather talk to like minded people who are just as enthusiastic about them than have it slagged off (generally by people who have never even driven one )
Having said that I still have a mk2 Escort and when I am looking for inspiration I will come on here and nose through the resto section, and if and when I get the enthusiasm to restore it then I will start posting again.
Even if you did 'allow' the later fords on here, doubt their owners would be made to feel very welcome so on balance it is best left as is.