Let me first of all say that I don't agree with what was done, and that I hope they find those responsible and prosecute them to the full extent of the law (although I expect they will argue they never expected to hurt anyone, just disrupt the race?). From their point of view it presumably resulted in longer road closures and disruption so can't have been too effective unless the idea is to scare off the event for next year.
Whilst yes it does bring in good money for the local economy, in in particular parts of the tourist sector, there are other parts of the community who do suffer and presumably believe that any net benefit to the economy isn't reaching them. Imagine if you run an ordinary business that doesn't benefit from cyclists being in the area - you loose a days trade, or if you are part of the angling tourism industry that is popular in the area, you may loose a whole weekends trade etc. Now imagine if you live in one of the villages cut off for 3+ hours for the race to go through - this isn't London, if the roads shut there is no way in or out the village - you are a prisoner so that a bunch of skinny guys in fluorescent Lycra can rush through the village. Then you believe you've made your points to the local Council but they ignore them and close the road anyway (possibly, according to some reports, without following the legally required procedures).
The alternative of running it with the roads open actually seems even worse to me - 3000+ bikes on those roads would to all intents and purposes close the roads for hours anyway.
There may be better ways of managing it etc - but its a fairly remote area with limited policing/resources and few alternative routes for getting people and equipment around the course to control it.
Would we all be so outraged if it was a horse race or long distance run that was being disrupted / disrupting the local services.