People who believe bitcoin has no long term future are unlikely to participate in the system in any sustained manner. If you believe bitcoin is just a scam you may participate in the periphery trying to make money but logic will dictate you constantly keep one foot in the doorway. You will hesitate at being involved in anything but the most superficial manner.
Probably you will choose not to invest at all but if you do then you are likely to cash out of the system at some point choosing to take your profits and leave the "tulip bubble" you have no confidence in. In this manner those who do not appreciate the underlying consensus mechanism will be diluted and replaced over time by those more interested in long term cooperation and building value.
It helps to understand what group selection is. Here is a basic introduction:
https://www.scientificamerican.com/article/whats-good-for-the-group/
What you say doesn't contradict what I'm saying. You may claim that there is a hard core of "true believers" which ARE indeed a community. Most probably, yes, there is probably a hard core community of true believers. However, the questions are:
1) how much of the ecosystem do they make up at any given moment in time
2) what influence can they have on the ecosystem ?
The way bitcoin is designed to be, turns around antagonism: we all want to possess coins, and if you possess a coin, I don't and vice versa, which makes us de facto antagonists ; there is competition in proof of work mining and the gains that go with it ; and deep down, it turns around speculation (which is a zero sum game). There's nothing in bitcoin that is designed to be cooperative, apart from having to stick to the consensus protocol for reasons of greater loss if you don't.
1) How large is the community of "true believers"?This is unknown but I suspect the "true believers" control a huge percentage of the bitcoins and this is a good thing.
Bitcoin came on the scene as the obscure technical pet project of idealists, anarchist, open source advocates and libertarians who wanted to improve the world and reform the status quo.
These "true believers" will over time take on an altruistic role to stabilize and maintain the system. If you read my link on group selection above they are the functional equivalent of the
fluorescens that maintain the polymer.
2) What influence will these true believers have on the ecosystem? They will have an ever growing influence because true believers form a large percentage now and they stick around while those who erroneously think this is a zero-sum game are unlikely to enter or will come and go.
Yes there is competition and speculation. These fuel interests and motivate people to enter and explore the ecosystem but they are ultimately secondary. Competition of this kind fuels growth but as bitcoin block rewards dwindle to zero and knowledge of bitcoin becomes increasingly common these speculative opportunities fade unmasking the ever growing network of cooperative win-win interactions that represent the long term value of bitcoin.
Bitcoin is a self reinforcing consensus mechanism that ultimately screens for cooperation. There is a necessity for a degree altruism that is built in. This is most easily seen when looking at nodes. There is no financial incentive for any individual to run a node yet there are thousands of them despite that fact that pure economic self-interest would dictate free riding on someone else's node. The bitcoin consensus system is cleverly piggybacked on a delivery vector of speculation leveraging human greed to attract broad interest while selectively retaining those most interested in long term cooperation.