I just read the Illinois CAI chapter’s amicus curiae brief in the IL Supreme Court appeal of the groundbreaking Spanish Court v. Carlson decision. The court held the HOA liable for violating contractual obligations to repair and maintain common areas, and homeowners could withhold assessments.
Speaking about the need for timely payment of assessment to keep the HOA going, CAI argues,
The very real impact of the Second District’s decision is peculiarly analogous to our government’s need to collect taxes free from objection by individual taxpayers. Surely, if people could refuse to pay taxes and then defend against their collection based upon a claim that the government had been negligent in the maintenance of public spaces and providing services, the government would find itself in dire financial straits and unable to fulfill its obligations.
The other decision in this 2012 case prevented the HOA from using the draconian measure of “forcible entry” – occupy the unit — to get the member to pay right away. CAI’s argument for the HOA was that forcible entry was a valid tenant-landlord action, but the court had held that not paying rent was also a valid landlord-tenant action.
The major selling argument for CAI’s being “a friend of the court” is its repeated claims to speak not only for the HOA, but for the members, too. CAI offers the same ol’ impression that it is an educational organization and not a business trade group that lobbies for the business interests of its members. And as such, why is it defending the consumers of its services, the HOA? We know why? Does the Illinois Supreme Court know why?
The Institute’s [CAI] mission is to serve as a national voice for those involved in community associations, including homeowners, governing boards, service providers, and vendors. (My emphasis).
The Illinois Chapter’s mission is to provide education and resources to Illinois residential condominium, cooperative, and homeowners associations, as well as represent their interests and the interests of Illinois community association members on issues of legal importance. (My emphasis).
However, the brief is full of arguments supporting the HOA and it right to use the draconian measure of forcible entry, while denying the contractual right to withhold payments when the HOA defaults on its obligations.
See Court decisions: HOA Enlightenment Movement vs. the Dark Ages; CAI amicus brief
HOA Constitutional Government 
I would say this is very important. Judicial Estoppel will prevent them from claiming otherwise in other cases, and this might subject them to a Constitutional challenge that they cannot defend.