This was the case pre MoP, but in MoP enrage timers are so tight that if 1-2 dps dies in 25m (on progression content) you often have to call a wipe just like in 10.
A mistake in 10 is just as damaging as in 25 in the current state of raiding...the only situation where I'd agree with you if you only have 1 CR in 10 and that person happens to die, but I'd imagen that that situation doesn't happen often unless your guild doesn't know how to make a decent setup.