I guess the advantage to car tire valves (or schrader) is you can easily overinflate them at a gas station instead of just buying a pump which someone would want to have anyway and if you have a frame pump with schrader it is harder to inflate then a presta valve. You also actually need the plastic cap to keep dirt, mud, grime and ice out of the valve stem, which does open the possibility to replace the valve caps with those stem lights that sometimes work but usually don't. Oh and if you are running them on a narrow road rim the rim is weaker due to a larger hole and less material around it which with higher pressure is likely to lead to cracking.

If you put the pump head straight on to a presta valve and pull it straight off you won't get anything bent. If you wiggle and jiggle any valve it is likely to break or tear (tearing I see a lot more with schrader and bent cores I see more with presta)