right, there will definitely be huge hubs. what you didn't even try to demonstrate is why can't there be smaller hubs?
> it just progressively works worse and worse. Doing multiple routes atomically just gives you more reasons a single payment can fail.
no, exactly the opposite is true. in case with single payment for X satoshi you need to re-try it multiple times until you find a route that has X capacity on every hop. with atomic multipath payments you need to find N routes that support X/N capacity (much easier) and if any number of those fail you can retry only those failed parts, so after 2-3 iterations your entire payment succeeds.
Maybe you are right that I do not know enough about the Lightning network, because I was not aware there was a vulnerability that big and easy to exploit built into it.
p.s. i'm sure you can google about DoS attacks on lightning and how to deal with them yourself