To be fair, quite much of the complexity will probably be handled seamlessly by the software. I expect smart wallets to automatically establish and overfund a channel whenever paying to a lightning recipient, and distribute funds over lightning and mainnet using some "sane defaults". There will probably also be services available for converting lightning-funds to mainnet-funds instantly.

That said ... one of the points I like to make is that lightning isn't so different from an alt-coin. I don't see any reason why lightning should get more popular than any other altcoin. It's pretty much the same chicken-and-egg problem.