I was reminded of this quote while reading Scott Berkun’s The Myths of Innovation:
And it should be realised that taking the initiative in introducing a new form of government is very difficult and dangerous, and unlikely to succeed. The reason is that all those who profit from the old order will be opposed to the innovator, whereas all those who might benefit from the new order are, at best, tepid supporters of him. This lukewarmness arises partly from the sceptical temper of men, who do not really believe in new things unless they have been seen to work well.
-Niccolò Machiavelli, The Prince
Shorter version: people are self-interested and risk averse. Replace “form of government” with whatever you like (product, technology, process, etc.) and the quote is equally as valid today as it was in 1513.