I think SatoshiDice or one of these gambling sites, did the same back in the day and everyone complained about that. Why put the Blockchain
under unnecessary strain? { How would this work with LN? ... because you need this to be linked directly with the Blockchain. }
bitcoin devs would have to find a way how to make the network handle an ever-increasing number of UTXOs. If this really is a threat to Bitcoin then the adversaries of Bitcoin would be doing this for long time already. So no worries here.
Lightning network has nothing to do with it. TXs made in the LN won't be saved on the block chain. Lightning network is bullshit anyway because lightning is a code word for banking. It's the banking network that they want to turn Bitcoin into. So that eventually only banks would be able to make bitcoin transactions and therefore have absolute control over Bitcoin. The block size should be increased so that Bitcoin would scale on-chain. Payment channels are a good idea and should be properly implemented as part of the Bitcoin protocol not in an ugly hack known as SegWit. I'd suggest everyone to reject SegWit, stop using bitcoin-core and instead switch to either Bitcoin Classic or Bitcoin Unlimited.