i'm glad you asked.
say for example toilet paper was free paid for by your taxes.
would toilet paper use go up or down?
of course it would go up.
and it's not like some people are not using toiler paper now so that explains the increase.
the increase is because it's "free". and that encourages waste.
same thing with buses. kids that were perfectly fine with walking 4 blocks will now take the bus. buses will have to be added. more pollution.
i've yet to hear of even a single community or advocacy group that asked for free or cheap buses. it's a political invention.
Those are a lot of assumptions. Yes, there will be people who replace a walking/biking trip with a transit trip (UVic saw some of that with the UPass). But the benefits are huge.
As for advocacy groups, I can't speak for any transit groups, but I can speak about bike related matters. If the politician is already pushing for something you support, there isn't much point is stirring up your supporters in support as well, as that just exhausts them.