We all know deficit hawkery is bullshit, in part because deficit hawks are always advocating for tax cuts for rich people. But, similarly, they hate tax cuts for poor and middle class people. The problem with tax cuts for poor and middle class people as stimulus is that Republicans wouldn't go for it, the deficit hawks would poo poo it, and your friendly neighborhood totebaggers would see it as exploding the deficit or some such nonsense.
Anyway, I guess my point is that, yes, of course I'd cut taxes at the lower end of the income scale if I could. But I think it's about as likely to actually get through Congress as infrastructure spending, so why not spend time advocating for that.