I've been to houses where the antenna was hit. It melted the insulation down on the coax and EXPLODED the splitter and anything else attached.

In an electrical circuit where there's a low resistance path to ground and a high resistance one, yes, MOST of the electricity will pass through the low resistance path (the ground wire). However, a fraction of the energy will pass through the high resistance path, and a fraction of a lightning strike is still more than enough to cause physical damage to electronics.

We had a lighting strike on our property a few years ago; the strike hit the ground very close to the buried wire for the dog's invisible fence and also within a couple of feet of where the cable TV coax goes through, about 100 feet from the house (we use cable only for internet, it's not hooked to the TVs). In that case, not only was there a good path to ground, it was HITTING the ground. Even so, just the side leakage from that strike snuck into the coax, blew the splitter apart, fried the cable modem, went through that to fry the router, went through that and blew the ethernet ports on 3 machines. It also got into the buried invisible fence wire and destroyed the insulation along the entire 1500 foot line as the charge broke it down every few inches, and even with all that leakage into ground, enough energy made it into the transmitter box for the fence to actually physically blow components off the circuit board, melt the wire going to the power supply wall wart, blew the cover off the wall wart and shredded the wires in the transformer inside, and make it through the garage power lines and fry one of the two garage door openers.

That was just the side leakage from a strike. Somehow I think that if I had a direct hit on the TV antenna, I would have had at least a little damage to the TVs in the house. Or the rotor control box.