Indeed i keep DOGE for trade and will buy more at 20 satoshi. LTC is not my favorite either but will take it for 0.003 btc.
DOGE and LTC are big names and long history (a brand has value). I don't think those coins disappear. Also i prefer those coins above new liquidy coins.
The only cryptocoin that has any value in its brand is bitcoin and nothing else. LTC and doge are scamcoins like many other thousands of crap and useless coins.