Since I have been banned from posting comments at Praytell, because I make so much good sense that offends their open mindedness except you, you know, when they aren't, I'll have to answer Jonathan Day's thought provoking post at Praytell, here.
I have consistently held that both forms of the Mass should coexist and where there are multiple Masses in a parish at least one should be offered in the "unreformed" Rite and the other saraments if requested.
No future pope will abrogate the latest incarnation of the 1970's Roman Missal. He might reform it to be more like the unreformed Mass and then abbrogate the 1970's and 1962 Roman Missals, who knows?
But if the 1962 Missal were to return as the Ordinary, normal rite of the Church, certainly the 1970's Roman Missal should be allowed in an "extraordinary" way and in parishes with multiple Masses, at least one 1970's Roman Missal should be allowed and the other sacraments for those who request it.
Of course, if the priest himself doesn't want to celebrate the 1970's Roman Missal, he should find someone who will assist him in providing it even if only once a month and at an odd hour.
Certainly, though, those orders that specialize in the 1970's Roman Missal should be allowed to establish parishes or mission that cater exclusively to it, perhaps buy old closed 1970's churches and reopening them or purchasing a beautiful closed gothic or Romanesque church and Wreckovating it for their new mission. But it should be allowed as some dioceses allow FSSP and other like them to run parishes.