Imagine a wallet app that has a a "prepaid" card function in it. So, you simply "top it up" with a certain BTC value (ie. putting funds into a channel, which happens behind the scenes, hidden from the user)... User then walks into cafe, selects that particular "card"/address/whatever from the app... boom... LN transaction.
You do realize that this 'prepaid card' of yours would cost the on-chain fee? And what happens when there's not a route available to your target?
some of the "issues" that have been raised, aren't really issues.
So far you haven't really brought up any good arguments against them.