That is so untrue. Farmers have used hot wires for yrs. Do you think they went around baiting them?Electric wire without bait would be completely ineffective against bears. Also bobcats. Also foxes. Also dogs.
About the only critters stupid enough to engage a hot wire without any bait that I can think of are humans and cows.
Bait on a hot wire is not needed. Why would you want to entice predators closer to your setup. Several friends of mine are beekeepers. Electric fence around there hives. Never a strip of bacon or any other bait used. They have seen bears cautiously approach and get zapped. Never a breach.