Anyway, the addition of LTC is great; fees for ETH and BTC are crazy high for the moment so smart move from Roobet by implementing litecoin. I hope they will add in a later stadium other coins with low fees like DOGE or TRX.
For me, LTC is enough if the withdrawal fee is low, it just needs new features from Roobet in the future, that's the most important thing.
I think it is always better to have more altcoin deposit options. Besides, implementing additional altcoin will at least gives an invitation for those altcoin holders to play in Roobet. It is like adding a target audience for the site. And I am pretty sure that there is always a gambler in every huge altcoin community, so having more possible players won't hurt for sure .