It's difficult to use, it requires always-on nodes, there appear to be multiple failure modes where funds can be lost to the counterparty with no recourse, and it requires the commitment of large amounts of currency to fund its channels and make the system work.
It's basically a joke at this point.
Not _that_ difficult. It's more complex to set-up than using Bitcoin directly but with an analogy to savings and checking accounts I think most people would be able to use it.
> it requires always-on nodes
First of all it's not always on, a phone that connects once a day or once a week is fine (the period depends on the channel parameters that your wallet software uses).
And even then that's only if you want to 100% trustlessly receive funds. To send you don't need to do it and by using watch-towers you can receive without having to periodically go online as well.
> and it requires the commitment of large amounts of currency to fund its channels and make the system work.
Only as much as you want to send.
> It's basically a joke at this point.
To people that haven't tried it or are overly critical of an in-development protocol with a small network of interested volunteers behind it.
Or in a broader sense: "De-regulated money transfer of any kind" -- for which the costs and risks of a cryptocurrency transaction are an acceptable tradeoff.
But for vanilla payments -- apparently they aren't (and never will be).