1) The article touched on legal reasonability, but 2) the thing I would think would carry more weight is, I doubt the HOA contract people signed had any verbiage surrounding this topic. Unless it said something along the lines of 'by signing this you comply to future revisions that will supersede the current contract'. To me, #2 would be where there is more legal standing. Now if these are rental situations, fine, don't want to comply...enjoy finding some place when your lease expires.
I always said I'd never live in an HOA either, and agree the article is stupid, and the reason I always said I wouldn't...but the neighborhood I'm in now has one and is pretty relaxed. I have 5 vehicles parked outside, 3 of which don't run and haven't even been tagged in 3+ years. The focus for my HOA is more property presentation to maintain surrounding property values...ie condition of the house, condition of yard and paying a couple hundred bucks a year to pay for street lights/landscaping in public areas. There was one neighborhood I was looking at though, that dictated what direction mowed your lawn each week, and averaged about 4 violations/month and would go to court over it about once a quarter. So there are good and bad HOA's. Based on what my attorney's have told me, the key to enforcing HOA bylaws, is enforcing the HOA with no exceptions...if someone can provide proof that Sally got away with the same thing, or even that another rule is ignored or not enforced, the whole thing can come crumbling down.