While you're right that until we're in the $Bn of value locked it isn't a concern -- it is a big stretch to believe that the pleb culture will scale if stablecoin adoption grows substantially on LN.

By definition, if we get more mainstream adoption we will get less small-node/pleb culture.

Focus on the overarching human qualities - greed and fear; This itself heavily incentivizes choosing the chain with the stablecoins.

StanKozlovski

bitcoin

Lyn Alden AMA

lynaldencontact

It's something to monitor, but the difference is that Ethereum is primarily meant for apps to build on top of it, while Bitcoin is primarily meant for hard money and by extension apps can build on top of it. Stablecoins on Lightning would have to reach tens of billions of dollars in value before I'd consider any concern in terms of its impact on forks. Even then I doubt it would be an issue due to bitcoin's small nodes and pleb culture. Bitcoiner's won't make any network sacrifices for stablecoins.