Coin price go up and down and many will eventually go bust. Can they guarantee long term survivability of scrypt coins?
When they say "always profitable" what they mean is that the miners will always make more BTC than they will charge you for hosting it. It doesn't mean that you will get the BTC back that you invested in their hardware. Which basically means that eventually they will charge you fractions of a penny a day so that the BTC earned/day > BTC price for hosting/day.
Don't think that you will definitely get all your BTC back that you paid for the hardware.
Then the company is misleading the buyers into thinking they will definitely get back more BTC than they put in.