The idea is for you to buy zen and trade it for dilithium on the dilithium exchange, that is the whole idea, the only idea.
Season 7 is 100% clearly a decision made in the boardroom to increase revenue and strangle the enjoyment of free play.
This does not mean that casual players can't have fun. It means serious players who used to earn dil/ec from STF's (an enjoyable challenge) are now forced to do extremely dull, pointless, no-tactic Fleet Events or, far more importantly, SPEND SPEND SPEND.
I believed in this game and, as such, spent my hard-earned on Zen. No more, as I believe Cryptic must have been bought by Bigpoint (actually owned by GE Capita)
"Diversity" was their excuse for the S7 STF changes. "Greed" was their actual motive.