It depends how you look at it I suppose.  I first went as a little kid in the mid-60s and it was hugely busy.  The crowds for Hailwood's return in 1978 had to be seen to be believed.  For me the 80s were a fantastic time with the variety of machinery and Joey at his best.  Big crowds too.

Trouble is now they haven't got the capacity to cope with a larger number of visitors.  There are very few hotels left and only two boats.  I'm sure they could get a lot more bums on seats if they had a better tourist infrastructure but that will probably never happen again.

Yes, there's more media interest than there has been for a bit but the media is very fickle and that interested could evaporate some day.  I'm going to sit on the fence and say there was a 40 year peak between 1950-1990!