I'd add this qualifier: If Cardinal Hoyos is the next Pope, he will try to regularize SSPX to the extent he can.
And, yes, they should have accepted the apostolic administration. That's the best they can realistically hope for, unless they intend to remain in an irregular status. It would have been beneficial to the people who currently attend their Masses, to the people who are denied an indult Mass (or for whom it is extremely inconvenient), and to the Church as a whole.
"You'd better do any "deal" you're going to do with JPII. His successor is likely to tell the SSPX to take a hike."
What worse can another pope do? This one has charged the SSPX with schism and its leaders with excommunication--falsely. And it is precisely because the SSPX stands on solid ground morally that they remain invulnerable to subsequent attacks. It is Rome that needs to repent, not the Society which has kept the faith.
As for the current status of SSPX--how would an apostolic administration be better than their situation right now? Right now the Pope himself has marginalized them, casting them from himself unjustly--which has freed them to expand and oppose his reign of novelty. It has also allowed them to protect the faith in its purity--as it was practiced and believed before the modernists took over.