The reality is that folks like "the_falcon" are the main reason why the sales cycles are longer. If they wield any amount of technical sway, it becomes orders of magnitude tougher to close a sale when they lay down deliberate & contrived (test) barriers. Oh, and they love using the POC technique to waste your time either solving their problem for free or finding out that they didn't really have their requirements fully understood.
Coming from the other side, the reason the POC is so important is because the reality is that we need to get the tech into the hands of the engineers so they can implement it, break it, and then run it for 6 months and troubleshoot it before they know if it's A) any good to begin with and B) a good fit for the problem they want to solve, and they have to do that with your product and whatever competitors are nearby in the Gartner MQ.
I know the sales guys work for their money, but I don't think the above is alot to ask for what could potentially be a quarter of a million dollars in recurring annual revenue.