Merchants are not accepting bitcoin due to some kind of believe system or a mentality they are having regarding cyptocurrencies than the true reality because if some one deny bitcoin or any other altcoin due to a loss by trying them by adopting in there businesses it is acceptable but many doesn't do that and spread false information regarding bad side of cryptocurrencies for no reason so majority of merchants deny crypto for no solid reason but due to false rumors from media and the mentality or believe system that they have build according to those information