I understand that (and it is a big commitment), but if they lived for a decade in a country and like it, why not? Seems like a better option than mucking aroun

I understand that (and it is a big commitment), but if they lived for a decade in a country and like it, why not? Seems like a better option than mucking around with visas and residence/work permits. I mean, this ILR gave them right of abode (if I understand correctly), and now they changed the laws so they can't work legally without a new document. What guarantees do they have that requirements for permanent residence won't change again in the future?