Litecoin has a fraction of the transaction fees of bitcoin, so instead of buying something that costs $10 and paying about $1 in miners fees, with LTC you would pay a few pennies at most. Granted, most retailers only accept Bitcoin if they accept cryptocurrency at all, but this may change as more people use LTC for smaller payments.
They're "optional", but the miners can pick and chose which transactions they include in a block, and the larger the fee they get from the transaction, the more likely it is to make it into the block.
They are optional but it is no longer safe to send a transaction without fees as the code in Bitcoin that allowed for free transactions if they met certain rules has been removed.
You might get lucky but you can always resend with fees to push it through.
I think they may be trying to put pressure on China to go with Segwit. This move would show Segwit's feasibility when it gets activated in a couple of weeks on Litecoin.
PS: I am a Bitcoin enthusiast, and I am not criticizing Litecoin, I just want to understand the possible advantages it could have.