the rate at wich bitcoin are mined by miners is something of concern for btc traders and investors coz the rate at which btc are minned is too high so after few years btc will increase in quantity and lose its value.
Looks like someone didn't do his/her research.
While bitcoin's hashrate increases due to more people trying out mining, the difficulty also increases, hence also lowering the bitcoins being minted. The difficulty gives bitcoin mining a sort of balance. And yes, the quantity will increase. But along with it, demand also will most probably increase, as long as mining difficulty. So it definitely wouldn't lose value. Not to mention bitcoin is only capped at 21 million.
https://blockchain.info/charts