I do understand what you are proposing.
However, Litecoins simply suck and that is why there is no positive feedback.
Vulnerability to mining monopoly
Similarly to Bitcoin, Litecoin can be attacked by a rich entity (on the scale of big corporations and governments). Also similarly to Bitcoin, this attack becomes more difficult to orchestrate the higher the hash rate of the network. However, because Litecoin is designed to be inefficient on all common computer components (both CPUs and GPUs), a malicious entity needs only produce a single piece of specialized/custom hardware to overtake all the commodity mining systems combined.
Another problem with changed algorithm is that
AFAIK Litecoin cannot be merge-mined together with Bitcoin, which sucks even more.
Right now any cryptocurrency can be attacked by a rich entity. There is
no way to prevent this except to
hope the network hash rate on the honest network side can remain superior by it becoming increasing cost prohibitive to challenge it.
So why is it perceived that something like Bitcoin can achieve network supremacy? Ponder that answer, seriously. Consider also how people are reacting to ASICS. My own belief is that as Bitcoin adoption grows so too will the resources available to defend it, not just by incidental market mining, but strategically coordinated network defenders. Governments are powerful entities with lots of money, resources, and state of the art technology.
Any specialized/custom hardware produced to target bitcoin OR litecoin would also be available to the honest network. As far as merged mining that is not a problem if both currencies gain mainstream adoption, for example. Just think about the math for a minute. World government regimes number in the hundreds, but regular people number in the
billions. It wouldn't take long for any cryptocurrency to have seriously cost prohibitive attack hashing rates once usage numbered in just the tens or hundreds of millions. It doesn't take the hash rate of the entire world to be cost prohibitive to attacks.
I've also explained in that post how a new model of currency usage (storing limited wealth in cryptocurrencies) reduces or eliminates the effectiveness of any 51% attack.