Personally, I think it is just a matter of personal choice.
To be a ROV pilot, you have to love mechanical and electrical stuffs a lot coz you will be dealing with them a lot.
To be a CD, you have to love the sea a lot, coz you will be in it a lot, you gotta love rigging, you gotta love manual labour..arduos taks...

In term of pay, I have yet to come across a ROV pilot becoming a CD, but I have heard of many CD become ROV pilots..so..go figure..

In term of risk, sitting comfortably in the dive shack (aka ROV Pilots) versus toiling under hot sun and rough seas (CD)....and yet again..u can figure that out for yourself as well.

Now..having 2nd thoughts about being a Diver??.

CHeers