Can't speak for the OP but here are some of my issues: 
-it is one of the only credits that is remotely universal / isn't really boutique as EVERYONE who rides transit can benefit.  But we can't have fair... they're taking this money back and giving it to TRULY BOUTIQUE credits elsewhere (daycare; as of yet undefined "woman-centric" freebies...)

-it is of real assistance to middle class people but also (and maybe I'm being selfish, feel free to explain how) people who are LESS than middle class.  Again, shuffling it from somewhat universal to more vote-buying.

-it DOES help push people towards transit.  This excuse of a government likes to cite "evidence" but cherry picks the one study out of many which supports them.  How about evidence from the oft-loved Europe where better subsidies drive ridership.  As opposed to -for example- the TTC which is the least per capita funded transit in North America and pretending to not understand why ridership is low and dropping...