As previously discussed here, there are (generally speaking) 3 types of "ground": 1) Electrical Safety, 2) RF, and 3) Lightning. Nothing says those are all the same thing.
True.So, all electrical safety grounds should be tied to the same thing, or bonded together.
Probably, "because the books say I should". I don't believe everything I read in books, and especially what I read on the Internet(s). ;)Now, that being said, why are you grounding your equipment?
I've never bothered to run any additional grounding of any kind. In certain situations like 2nd floor shacks, they will often cause more problems than they solve. My rule of thumb is to add grounding only when there's an actual problem.
My equipment is plugged into a 3-prong AC outlet, which is my Electrical Safety ground. My antennas are dipoles and loops (which are balanced antennas that require no RF ground), and a couple of verticals with their own radials, that serve as the RF ground for those antennas. As to lightning ground, in the 10 years I've been here, I can think of only 1 strike that came close. It struck a neighbor's tree, which is higher than any of my antennas. I also have a 1,000 foot FM broadcast tower less than 1/4 mile from me. If anything is going to get hit, it's going to be that structure.
As always, YMMV.