Here is an "outsiders" point of view (I'm from eastern CT and have never been on Candlewood)

It's definitely a lake tax, which is kind of understandable. Candlewood seems like a big expensive resource to manage (just look at it on a map it's huge for around here), which is a lot of the local towns to pay for.... on the other hand how much money has the lake made the surrounding towns? Would properties values be as high without the lake, I doubt it. All that being said it's probably more expensive to manage that resource today than any other time in history. We pay attention to a lot more variables nowadays, perhaps this thing has reach a tipping point between cost and benefit and this is the center of the issue in my mind.
The towns carried the financial burden of carrying the cost of management because it was worth the benefit for their property values, and lake users got a free ride. It must have reached a point where the towns are not seeing the benefit for their cost anymore and want the lake users to start paying for their benefits. What a tangled web we weave.
Regardless of cost verse benefit, I would be concerned with where the money is going, what the heck is the Candlewood Lake Authority. Do it's members stand for election or are they appointed? If appointed, who do they answer to towns, the state, both. It needs to be clearly defined and democratic it they are going to be collecting a tax.