I think you are correct on the cost effectiveness, however these are cheap.  For a newb it is a way to dip your toe in, learn about mining.  Possibly have a little faucet.  Buying an L3+ for example, is a big endeavour.  More cost effective for sure, but it really is a big ticket item.

I think these will pay themselves off, and after I break even well, that is a bonus.  Over time Litecoin will go up, and I think I can make some $$.  I'm not depending on it though.  I'm just shooting to break even and learn something in the process.