If your property is identified in the CC&Rs, then you are legally part of community are probably on the hook. The fact that a property owner doesn't actually use the common areas isn't going to discharge their duty to pay common area assessments if their property is bound by the CC&Rs. That being said, you should have a lawyer review the CC&Rs for you to determine if your property is really bound, and if the HOA is acting within its powers by assessing you.
I agree with the prior attorney. The issue is not whether or not you adequately use the common areas in order to be assessed, the issue is whether or not the CC & R's apply to your property. You should consult with a real estate attorney to determine whether or no the CC & R's were properly recorded against your property prior to your purchase, whether or not the rules creating the assessment were properly enacted, and then whether or not the assessment was properly assessed.