I am not sure if the paper money was rejected before accepted globally. But I believe in a theory that when you discover something new, then at the very beginning it would be rejected globally. But, slowly it would be accepted by peoples. So same theory is applicable for Bitcoin as well. In the beginning, no one accepts it, slowly it has been spreading globally. So many negative and positive comments will come from different peoples but seem it's not affecting Bitcoin. Seems Bitcoin does not care about all the negativity. Hope once a time global population will be more encouraged to know about Bitcoin.
The reason this appears so, is people are stubborn, but also don't like change. So, whenever there's a new technology, or concept especially when it introduces evidence that their current belief system, or technology or whatever they are following is doing it wrong, or at least inefficiently they can become somewhat defensive of it. For example, I know a lot of people who complain about the fiat money system, but are completely hostile to Bitcoin simply because they don't understand it, and its trying to change what they are currently using.
This is why we have pioneers in almost every department. they are the ones that take on the challenge of furthering the development of these alien ideas, and in time make it simpler, and easier to understand, which in return increases adoption rates.