Speaking as an Ethereum core developer here - I see a lot of misdirected criticism and misunderstandings of Ethereum and the platform in the wider tech community. That said, your criticisms here are absolutely spot on; these are definite issues with Solidity as a smart contract programming language.
The only small correction I would make concerns this:
> Functions can mutate state by default. Both are overridable by explicit specifiers, much like C++ "const", but you have to remember to do so. Even then, the current implementation doesn't enforce this for functions.
When interacting with Ethereum you can do two things: send a transaction, or call a function against your local copy of the blockchain. The former is mutating, costs ether (in gas fees) and requires the transaction to be included in a block. The latter is entirely local, cost-free, and any mutations to state are ignored.
The 'constant' modifier in Solidity serves only to tag the resulting ABI of a function so that calls to it from common interfaces default to local calls instead of sending transactions. It's not intended to enforce that calls to that contract are read-only, only to indicate to callers that it should be called locally instead of creating a transaction for it.
The only small correction I would make concerns this:
> Functions can mutate state by default. Both are overridable by explicit specifiers, much like C++ "const", but you have to remember to do so. Even then, the current implementation doesn't enforce this for functions.
When interacting with Ethereum you can do two things: send a transaction, or call a function against your local copy of the blockchain. The former is mutating, costs ether (in gas fees) and requires the transaction to be included in a block. The latter is entirely local, cost-free, and any mutations to state are ignored.
The 'constant' modifier in Solidity serves only to tag the resulting ABI of a function so that calls to it from common interfaces default to local calls instead of sending transactions. It's not intended to enforce that calls to that contract are read-only, only to indicate to callers that it should be called locally instead of creating a transaction for it.