The problem is not the county's. It stems from the relationship established, either expressly or impliedly, between the developer. Was there a duty, in contract, or as a matter of law, for the developer to maintain and pay taxes on the lake for the benefit of the homeowners? If that duty exists AND is one that attached to the lake, as a covenant (promise) or easement (permission to use by others) then the present owner will be obligated to observe that duty because it was not extinguished by the tax sale.
If the duty existed and did NOT attach to the property, then it is likely a matter between the homeowner's and the developer.
The county does not have a responsibility to review all of the homeowner/developer relationships underlying residential properties before issuing tax certificates that may eventually be redeemed for tax deeds.
Which is the underlying problem. Here we have a political matter which the county is not required/empowered to act upon. I would bet ten cents to a donut that some county offical was aware of this "opportunity" and passed on the information to a friend.