What don't you like about this?
It's far more private than a ledger of transactions everyone can look at.
We can discard our private keys after each payment and expect other people to do the same but with the LN we have to hold our key even if we have no balance in our wallet, if the key is compromised then the intruder will be able to gather some additional info.
Also, the merchants can't use the LN to pay their employees/suppliers because the amounts are too high, so how can they unload their channels to receive more payments? I finally think that a block size increase based on technological progress makes sense.