If you think that the cost, reliability and the user experience does not influence adoption, then I think that you are fundamentally wrong. Bitcoin can be out competed, if we do not increase the blocksize that is exactly what I think would happen.
Of course the cost, reliability and user experience do not affect adoption. Many people come to bitcoin just to contribute resource, not asking for service, because this is a trustworthy monetary system. Being service minded are typically cheap mindset from entrepreneurs
The fact is that people in bitcoin community (mostly libertarian type) will never listen to someone else unless they see it with their own eyes. And even if they face a problem, they will tends to use their own solution instead of others, there are many ways to solve a problem without touch the bitcoin protocol
Here is another thread showing that this kind of discussion is just fruitless
https://www.reddit.com/r/Bitcoin/comments/3yyvmp/they_think_satoshi_was_wrong/You are linking a censored thread where all opposing opinion is being censored, you should keep that in mind. Even quotes from Satoshi are being censored in that thread, I do not believe that such a place is productive for constructive discussion, this type of censorship is dangerous since people can become very disconnected with reality, arguments become one sided since they are not exposed to critical thinking, truth requires freedom to rise.
You are obviously coming from an engineers mindset, you are failing to see the human element in all of this. I think that most people would disagree with the statement that you made which I highlighted. I think that your basic understanding of economics is wrong. It also good to keep in mind that Bitcoin should be destined for world adoption and as such the concerns and sentiments of everyday and normal people are important, not just idealistic libertarians and engineers. Whom might have concerns that most people would certainly not prioritize. I would argue that most people would care more about being able to transact easily, cheaply and quickly using an SPV wallet on their smartphone as opposed to the ram usage of full nodes in datacentres for example.
I think that Bitcoin is intended for global adoption, which might be in conflict with the vision of some cyberpunks, idealistic engineers and libertarians. It does not help that many of these people are also Bitcoin maximalists, since then this radically different vision for Bitcoin would not need to be pushed so hard onto Bitcoin, it would make more sense for such people to turn to smaller altcoins which can go the route of security through obscurity and anonymity. As opposed to Bitcoin which I think should gain increased security through mass adoption, which also means keeping it and making it more appealing for the masses. Which most definitely does include cost, reliability and user experience.