I don't think that's what they're saying. 
I think they're suggesting that LN offers choice by way of having a product which companies can then offer by way of custody, but also said product can be utilised without such companies and taken up by ourselves. 

Whereas in Liquid you can't, at all, have that same choice. The infrastructure is a federation (of 16?) corporate entities. Users have no way to run their own infrastructure.

As much as we're going through a rough patch with lightning, truth is, EVERYONE is free to take their sats and run their own nodes, especially nowadays with things like nostr:npub1xnf02f60r9v0e5kty33a404dm79zr7z2eepyrk5gsq3m7pwvsz2sazlpr5 Wallet allowing anyone to run their own mobile wallet (it's still in beta, but close.) - That's the distinguishing feature here and as much I have my own uncertainties about lightning, it's something worth protecting rather than jumping boat to something that just seems to work, potentially because it has very little usage compared, without really looking behind those curtains.