A Lightning type payment channel is simply a write cache for the blockchain.
Do you know how much the write cache improves a hard drive's performance? Try turning yours off and find out.
Why don't you moan about the presence of write caches on hard drives, and spew FUD about how output operations to the write cache aren't real "on disk" transactions!

You know it's not real "on disk" operations when the computer crash or power short age and the filesystem end up corrupted :p otherwise you would just keep all the data on ram disk and just write on the HD on shut down

how safe would that really look

Write cache aren't not all that fud free

Now with journalized filesystem it mitigiate the possible damage, but having reliable decentralized journalizing on LN would mostly ruin the concept. And in this context having only private journalizing is not changing much.