1. I don't think there's anything wrong with changing the "mantra" as it were. People learn things, opinions change; do your own research and form your own conclusions/hypotheses.
2. There's no one fixed "mantra" of cryptocurrency. As you point out yourself, there's some people who see BTC as a store of value first and optimize for that, and I'm sure you're aware that that's at least not an uncontroversial decision. Different people have different opinions about a ton of different things like monetary supply policy, the importance of censorship-resistance, immutability, non-currency use-cases, etc.
2. There's no one fixed "mantra" of cryptocurrency. As you point out yourself, there's some people who see BTC as a store of value first and optimize for that, and I'm sure you're aware that that's at least not an uncontroversial decision. Different people have different opinions about a ton of different things like monetary supply policy, the importance of censorship-resistance, immutability, non-currency use-cases, etc.