Nope, I don't think there are any deeper reasons than people just trying to make money. 

This whole investbox thing has left a bad taste in my mouth since I've had some time to actually think about it.  I don't like how Yobit changed their campaign signature from cryptotalk to the investbox one, which is asking members to advertise something completely different and at the very least smells very fishy. 

People might very well be tempted to buy some of those non-existant shitcoins with "investment plans" on Yobit, in which case they're probably going to lose money when they try to sell those on the market after Yobit ends the plan earlier than the person thought.  They're only going to let you earn 5% interest daily for a few days at most--and notice how you can't withdraw any of those coins or even find much info about them.  It's all a load of crap, and any lingering respect I had for Yobit has basically flown out the window in the past week.