Sorry for the question, but 10 years in Brazil, why didn't you apply for naturalization?
I'm sure that Mike has his own reasons. I can tell you from my experience, that naturalization in Brazil is not an easy process, nor is it a decision to be made lightly.
Brazil is relatively generous in granting permanent residency, and comparatively restrictive in granting citizenship. Permanent residents can come and go as they please, and have almost all the rights of Brazilians, except voting, holding office, and competing for civil service jobs. Citizenship requires proving writing, reading, speaking, and understanding competence in Portuguese equal to that (by my estimate) of a graduate of a good Brazilian high school, as demonstrated on the CelpeBras examination, which is only offered twice a year worldwide, and has a passing rate of a little over 50%. Citizens between 18 and 70 years of age are required to vote in every election, or obtain approval for not voting. New male citizens of military age can find that they suddenly have a military service obligation under Brazil's universal service laws.
Some countries treat naturalization as an offense that automatically cancels a person's birth citizenship. Happily, there aren't as many countries like that as there used to be, but no one should begin a naturalization process without considering effects on their birth citizenship.
Brazil has tax treaties with many countries, some of which can result in serious disadvantages from naturalization. The US and Brazil do not have an income tax treaty (they do have a Social Security treaty), but they do give some credits to avoid double taxation, so often, naturalization can be a wash.. Brazil and Canada, however, have a tax treaty that is very advantageous to Canadian expats, and they need to consider very carefully the benefits that they stand to lose from dual citizenship. Those are just two examples. There are as many more as there are countries in the world.
Brazil has a relatively strong passport. This is an attraction for citizens from some countries. It's not a big advantage for citizens of English-speaking or EU and other Western European countries, though, and needs to be weighed against the possible disadvantages of losing home country diplomatic protections in Brazil.
I'm a dual citizen, Brazilian by naturalization. I love Brazil, I'm totally at home here, I've been coming here my whole adult life, I speak Portuguese like a Brazilian, and I obtained permanent residency under the old law -- but all of that probably still wouldn't have been reason enough for me to get naturalized. My husband and I are a same-sex couple. We're married under US law, our marriage is recorded at the Brazilian Consulate General in Chicago, and registered at the proper cartório here. We've never run into an instance of discrimination so far. But the current Brazilian Administration is openly hostile to LGBT people, and has substantial support in the Congress: probably not enough to imperil my residency and force us into a relocation decision that we wouldn't consider otherwise, but why take the chance? Brazilian citizens have additional protections against expulsion, and that's the reasoning that brought me to my decision.