IMO mint became popular, so people decided to clone it and see if they could pull off the same thing. And mint itself is just a clone of DOGE with some stake tacked on as an afterthought...gimmick.

In my opinion ALL coins should be both Work and Stake. Work secures the network and keeps a community active. It allows people who don't want to buy the coin outright to get some. Stake helps stabilize the price and rewards the holder of the coin for being loyal and using the commodity - ie not just dumping them as soon as they mine them, or as soon as the price jumps a little bit.  

These flash in the pan coins - where you can only mine for a few weeks are just all noise and no substance. I bet they're a way for early adopters to make a ton of money before they are dumped. Look at mint and blackcoin right now - pump and dump.  

Devs - coin makers - I'm calling you out.

• Stake should either be the NVC model - 100% yearly modified by stake difficulty - or 50+%
• Stake coins must have methods to contain inflation - destroy tx fees
• Stake age should be no greater than 30 days

All other stake is a gimmick.

Coins that don't pass the stake test use it as a hook to draw in the unaware. They throw words around like "investment," "gains," and "energy efficient." As a stake investor stay away from them. They will be ruled more by price fluctuation (pump and dump) than by stake and you will never recoup your investment through stake.  

Coins need a community - miners plus stake holders grows the community.
Coins need to be rare - not billions of coins within a few weeks or months.
Coins need to be fair - not hugely rewarding early adopters.
Coins need to be supported - good and active devs.
Coins need to be stable - work and stake that last for years.

Coins that pass those tests are worth investment.