Satoshi said things like this multiple times, and I think it was because he thought everyone would be more comfortable with SPV than they are. And the reason he thought that was because he thought fraud proofs (being ble to prove that a transaction is NOT in a block as opposed to the client being censored) would be easy to solve. Fraud proofs weren't easy to solve. There still is no practical solution for them.
Shit(fork)coiners don't think this is a problem. SPV works well enough for them, because 1) nobody actually uses their chain for practical matters and 2) their risk model is much more concerned with 50% attacks. Having to worry about fraud proofs would be a luxury for them.
The best way to prove your transaction isn't being censored is still to run some sort of node. BIP 157/158 block filter nodes improve the situation significantly, but eschew SPV inclusion proofs in favor of filters that help the node determine the probability that their transaction is in the filter created against each block, limiting the occasions when it downloads the entire block.