I'm sure there is good reason to be mining LTC. If you dont feel there is, doesnt take much work to redirect your miners to a different pool for a while.
in not a "feel" its simple math
if you mine litecoin you get X btc,
if you mine other you get >X btc
as someone mentioned small coins can't be exchanged at high volume for btc without crashing meaning its more profitable to mine with smaller pool
safest way is to point rigs to different pools, but people with only one rig are making a bet on pool's owner which not always working well.
last week middlecoin was better profit than others but this week it is not possible unless others will start mining less profitable coins.