It is still an improved version of Zcash.
What?! How is it an improvement?
Only thing ZClassic has really done is remove the founders fee.
ZCash is actually continuing development and making progress on new features. ZClassic hasn't had developers for awhile. I believe that prior to the fork Rhett was the only one working on it until mid December 2017.
If ZClassic goes up it may be because there is a theory that ZClassic will become a forking launchpad. They'll launch additional forks from it. So far we have both ZenCash and BTCP coming from it. There has been a suggestion to make a Litecoin Private fork next

Who knows if they will... If they make enough profit at this, why wouldn't they?
Is the developer of ZClassic who now left actually a good developer? He's quite a young dude who doesn't have a proven track record in crypto, does he? Zcash has a lot of funds and a huge team working continuously to improve the code.