Given that the average computer user is not very tech savvy, and is likely to succumb to malware and drive-by hacking attempts, what makes you think it's safer to encourage people to be their own custodians?
Or doesn't it matter at that point, because you're off the hook?
It's true that this isn't ready for the average computer user. But there are projects that I do think make it safer, for example dedicated hardware devices like the Casa node.
I think that as this technology (Bitcoin and Lightning generally) matures, we'll get better tools to make it safer for average users (just as we've done on the web).
Or doesn't it matter at that point, because you're off the hook?