Because I've actually seen one pattern of bitcoin's value. I'm still not 100% sure but it is a good profit scheme in a mid-long term run.
Actually it depends on how you handle the risks, most investing experts with their books and all often say the longer the investment, the lower is the risk. Not pretty sure if that's truly the case with BTCBTCBTC but I guess it applies.
bitcoin will continue to evolve and I think not only be stable hold at the same price as today. the potential for increased future is quite high. so bitcoin could certainly do that, the longer we invest will be more profitable.