Honestly have no issues with the changes.
It was redundant having two entire classes of weapons that close together in terms of fire rate.
I can totally understand the shift.
If all went to 150, we would basically have a never ending meta for hand cannons as no one would logically use anything other than those.
600 auto's and 150's would have the same TTK. There, you can chose either gun depending on preference. 1 has has harsher punishment for missing and the other has less punishment.
Making them all 150 would not have impacted Auto's that much at all or the meta.
People will still use handcannons because they feel better to use.
Remember when Luna and NF were top tier? there was 1 gun that compete with it and it was a 140: Ace.
Why? RANGE. They could just adjust range on the different archetypes OR convert them to 150's.
Only real point you didn’t bring up is that if you play a hand cannon correctly, you would not be putting yourself in positions often enough to let the chisel like damage output(Bungie’s word it, not mine) of autos compete.
Hell, scouts are lethal as hell but people play them in less than optimal ranges which is why they don’t keep up.
Some guns are hammers.
Some are chisels.