Ah, come on. I am the first person to complain about woeful misuse of money, but let's be realistic here for a second, exactly how much money would be saved by not having this wrap, and how much extra service would it buy? I'd be shocked if it was enough to pay for one day of operations. This is "milennials would be able to buy a house if they didn't spend so much money on avocado toast" level of arguing. If you have debts, should you never do anything nice for yourself or others, even though the money saved by not doing that would hardly be enough to get you out of debt?
Besides, as
@APTA-2048 correctly pointed out, this is a common thing across the world. In Europe, basically any city with an iota of civic pride wraps vehicles for Christmas, often in far more extravagant configurations than ours, even though none of their transit agencies post profits. (They also do other things Toronto thinks of as silly frills, such as having historic vehicles). It cheers people up (well, maybe not people who use online forums, but families, certainly) and it demonstrates some pride in what they do. It's great that for once Toronto didn't fulfill the self-hating, fun-hating Puritan stereotype and did something nice.