I know that many pilots don't want any smell of Jet A in the airplane from the fuel sampler or rags, as it doesn't evaporate away as fast as avgas, consequently will use any excuse not to sump. Letting passenger "comfort" dictate over safety.

I remember having the fuel gauge indication on one 727 fuel tank in Hawaii keep jumping up and down by 1000 lbs..... the lead mechanic told the other mechs "have you guys been sumping this thing? Go do it now"... sure enough, 15 or 20 gallons of water.