Sure safety is the priority, but if you want maximum safety, then leave the planes parked on the ramp 24/7. There's risk for everything, especially in flying. There's risk taxiing out, there's risk taking off, etc, etc, etc. Operating in the NE minus a TCAS maybe scary, but that risk can be mitigated in other ways if the TCAS is out, again depending what the MEL allows or doesn't allow. What I'm saying is that if you go out everyday expecting 100% protection from all the "aerial bogeymen", you're fooling yourself.
Using this logic, we never should've flown planes in the NE USA pre-TCAS era. And TCAS is only as good as the other guy squawking, as previously mentioned in this thread. I'm just somewhat amazed at the number of TCAS-dependent pilots there seems to be here. It's a useful tool, not a crutch.