Due to the nature of the beast, hardware can NOT be more flexible than software.  Granted some of the system/network issues associated with hard-forking a coin needs to be considered carefully within the software.  But the system considerations are not the indications of inflexibility of software.  Sure, the design cycle of ASIC is becoming much shorter but the inherent inflexibility of hardware hasn't disappeared.  If the hardware is that much more flexible than software, why not just implement the entire aspects of coin in hardware?