Let's catch some low hanging fruit:

"blockchains can’t do anything against ... plain old typos in a coin transfer."

It is difficult to use properly crafted software and form a tx to a non-existent address on Bitcoin. It is not impossible, but not easy. The typical consumer is not meant to use layer-1 finance tools in any digital domain, modern, traditional, or blockchain based. Its not that hard to conceive of Bitcoin banks which have the same protections whilst offering currency sovereignty impossible in status quo finance.

https://www.reddit.com/r/Bitcoin/comments/26s1i5/can_you_los...

"However, in the world of blockchain there is no human supervisory authority."

There certainly are. One of the biggest hacks in history was reverted by human supervisory authority and community migration. This is an extremely unlikely method to help individuals who make some any mistakes on layer-1, however.

"The absolutely perverted energy usage in times of climate change is only one of those (this is mainly caused by proof-of-work, still used by all relevant public blockchains, and general inefficiency)."

This is a 'using energy bad' argument. With this logic we can also write off automobiles, smart-phones, artificial intelligence, hamburgers; if you do not quantify the value vs. the cost you cannot make an argument. Crypto skeptics are usually incapable of steelmanning the value proposition of crypto and make circular arguments like "crypto is not valuable because it uses so much energy," or appeals to their own ignorance.

You can't say Bitcoin is inefficient if you don't understand (or demonstrate that you understand) what it does. Somehow skeptics believe the proper response to pointing this out is to retort "I know what Bitcoin does, it uses energy to promote gambling!" That is not the response of a tech literate critic.

"this is mainly caused by proof-of-work, still used by all relevant public blockchains, and general inefficiency"

Proof of work is intensely 'out of style' even in the crypto space and sans Bitcoin and its much smaller forks (which almost invariably use mere fractions of Bitcoin's energy) there are only a few new, layer-1, relevant projects sticking to proof of work. Equating the number of tokens which exist on smart contract languages to the amount of energy used by proof of work is deceptive.

"(By the way: some of the advantages promised by blockchains, but without the nonsense, is implemented by Merkle trees 9. They already exist since 1979 and blockchains build on their technology. But please don’t also start trying to use Merkle trees for stuff it’s not useful for.)"

This is nonsense. It's like saying you have all the advantages of a cart or carriage by simply removing everything but the wheels.

"The main objective of blockchain is to decentralize trust and consent (even that it doesn’t do well, as explained"

This was not explained (you only need read a few paragraphs to prove this), and the author failed to state the view they are claiming to lampoon therefore have not demonstrated they understand what they are critiquing.

Let's acknowledge what the blog post gets correct:

There was, and still is to a lesser extent, an epidemic of trying to solve problems by engineering a blockchain solution. The absolute culling of anything spurious from the last market cycle has greatly decreased those endeavors and most money is in tokens on existing layer-1 protocols at this point. Skeptics and believers alike appreciate that mentality being ousted. Decentralizing services doesn't require a new chain for every new use innovation. Most of the important decentralization can be done off chain since most data isn't so important as Bitcoin account balances.

There is a large number of speculative 'scams,' or more realistically failed projects up-selling their potential. The likelihood of one's success investing in crypto without having done significant research or access to a trusted person who has is low. If a team has found genuine innovation the messaging around it will immediately be co-opted competent and incompetent, honest and malicious teams. You cannot determine which teams are competent and honest from their messaging alone, it takes digging. It is not a welcome or recommended place for anyone who cannot do and understand the results of serious digging.

Take it from someone who believes in the value of blockchain tech and has undoubtedly spent more time than the author listening to other 'believers:' most people bullish on crypto share the same valid complaints the skeptics make (this author makes all the cliche mistakes on top of the valid ones).

Not only that, but those serious in the space welcome critiques of the technology. Blog posts like this which are largely fueled by emotion and ignorance are denounced by dogmatic believers and scammers for bad reasons, but they are also ignored by honest believers for good reasons. Honest believers are receptive to competent feedback but this blog post is more of the same ignorance.