TELEVISION shows. Whole reason for being? COMMERCIALS. Always keep that in mind. FIRST.
Entertainment for the masses. Never intended to be especially accurate when it comes to science. It simply wasn't an important goal.
Something being able to evade the transporter's screening process. Let's expand on that for a moment. Approaching a planet. Ship's sensors say Class M, atmosphere near Earth norms, nothing to indicate a problem. No environmental suits needed. Landing party beams down. And are promptly all killed because something was able to influence the ship's sensors to give false readings. Heck, with superior technology/abilities, the entire planet could be an illusion and the team could be beamed into open space without protective suits.
Considering what the show depicted, every single mission had risks. Big ones. 'Routine', itself, was a story conceit. Reality, with those conditions existing, and the potentials involved, would be very different.