The trouble with transponders and even lights is that if every obstruction was kitted-out the data would overload the pilot. The pilot is multi-tasking and in the event of equipment problems (or even marital or kid problems) he can't devote 100% of his brain to terrain clearance. If he did, the a/c would fall out of the sky.
Nothing about this tragedy that we've heard so far suggests to me that the present arrangements are unsafe or should be altered. Yes, there is always room for improvement, an evolution, but we don't need to worry the travelling public by suggesting that something is 'broke'. If is aint broke don't fix it.