There's no way that's true unless you live in a really messed up market, taxation-wise.
Here in the SF bay area I have gigabit internet through comcast and allow them to shove their "basic" cable TV service in my general direction (it's not even hooked up) because it 'saves' me $5 or $10 or whatever per month on my internet charges. (All I know is the total bill is $144 which is less than the advertised rate of $169 for Gigabit, but I've been through this excercise many times in the past 5 years, where I try to get JUST internet, and they offer me tv+internet for $5 or $10/mo cheaper; last time I didn't even ask for the full numbers)
Fees:
Broadcast TV Fee $8
FCC Regulatory Fee: $0.08
Franchise Fee: $2.01
PEG Access Support: $0.55
Local Utility User Tax: $1.55
State Sales Tax: $0.23
So, $12.42 in taxes and fees, only $8 of which is clearly related to broadcast TV (and here I'm assuming I don't pay that fee just by being a subscriber to a cable company, even if I get internet-only).
I plan on calling sometime soon to clarify, but I've done it many times, and it never saves me a penny.