The TT has always had its highs and lows. At the moment it is on a high. The DED will have you belive that the high is down to them. ( that might very well be true) But it only need one wet year ( like in 98) and you will see the following year plumet in visitor numbers.
Or watch what will happen if some of the big player no longer appear.
I thing Guy Martin retiring, J McG being injured, or Michael D not having a ride one year will knock off at least 5000 visitors for each rider, from coming over.
At the end of the day, whatever the weather, or what riders are racing, the true enthusiast's as apposed to the ' Event curious' visitors will carry on attending the TT for as long as they can.