> 1. It's not a currency. It's an asset;

It's an asset that can easily be used as a currency using technology like payment channels or rollups.

> 2. Reversible transactions for fiat currencies is a feature not a bug;

I can make my blockchain transactions reversible if that's a shared priority between all parties taking part in the transaction. I can even assign some quorum of others who can facilitate the reversibility process if we want. Blockchain is about freedom to choose what is important to you and not be forced to give control to some anointed third-party.

> 3. People who can't manage passwords won't be able to manage a wallet so mass appeal is always going to be limited;

Managing private keys can be difficult. Social recovery wallets make this much easier - you can choose to be the sole individual who can generate your private key, you can trust a group of friends/family members, or you can trust a combination of friends, family members, and private/public institutions. People who don't value decentralization or autonomy can let a third party manage their keys, and people who don't trust third parties can manage their own keys with a fallback plan if they lose it.

> 4. Crypto has its own vulnerabilities (eg 51% attack);

I don't think any informed member of the crypto/blockchain community pretends that crypto doesn't have its own vulnerabilities. What they talk about is the existence of vulnerabilities and the trade-off you take by using a blockchain. 51% attacks are very difficult to pull off in a meaningful way (rewriting history or stealing funds), but by using a blockchain you can own assets, do p2p transactions, and have a record of digital asset ownership on top of many other uses.

For many of us, the benefits outweigh the risks of a 51% attack or potential contract bugs, though many people who are now "investing" in this space don't understand anything about blockchains and treat them as money-printing machines, often using highly centralized chains that would be better run as centralized gambling services.

> 5. This whole system is hugely energy wasteful; and (here's the big one)

You are talking about a specific implementation detail of proof-of-work blockchains. Proof-of-Stake (PoS) chains exist, and even the second largest chain by market cap has been running its PoS chain for over a year and will fully migrate over to it within months (cue jokes about dev delays). Blockchains can and do exist in a form that doesn't waste huge amounts of energy.

> 6. Government action could shut down crypto tomorrow so how robust is it really?

I see people have already replied about this point. Certainly there are ways that governments could hamper blockchain development and adoption, though they could also embrace the technology. Blockchains were created to give power to people over the governments and large financial institutions that control them - sadly, most people in the space have lost sight of this and are focused on getting rich. In a world where all assets (including currency) will soon be digital, having government control over these assets is a huge risk to individuals whose governments may someday freeze their assets or fall to an authoritative regime that creates an economic prison where fleeing oppression means losing what you've spent your life working to earn. People should have power over their governments, not the other way around, and giving people a way of holding assets that are beyond government control is a great start.