A rather long way of saying "Get lost. Go find some other site that provides the same information without all the restrictions this site enforces". perhaps they are hoping that the unfriendliness of their site will not be talked about so much with the long winded message that some of their potential visitors would be unable to comply with even if they wanted to or maybe they hope it will reduce the possibility of their being sued due to their site discriminating against some disabled groups.
There was a kMart web site that displayed a message like that at one point. They eventually settled out of court for an undisclosed amount (possibly several million dollars) with one of the conditions being that they remove that message from their site.