There was a fairly recent interview with Mr Philips in BSN which gave an approximate breakdown of how the TT brings in revenue.  At least for now, it would appear that the return for the government from visitor spend is still greater that the revenue from sponsorship.  Visitors are no less customers of the DED than the sponsors are. 

I've spent my whole working life in customer related stuff of one sort or another and I've never come across anyone that shows such disdain towards it's customer base as the DED does towards people that contributed to iomtt.com.  This includes people that help to run the event (marshalls) and people that help to publicise it (photographers/journos) - help that is given entirely at the individual's own expense.

Disagreeing with someone is not the same as 'slagging off'.