Subway dude was probably told he had to meet his spinach quota or lose his job.
Either try to make the world a better place (it is possible, small things are not wasted) or be quiet and stop infecting the rest of us with your apathy.
Edit: I really must stop being an obnoxious arse. Let me try again, then. Comments like that are damaging and self-reinforcing because they demoralise. A lot of people care and are decent but will not try to remain that way if comments like this corrode them - why should they, if decency is met with nastiness? Why even try? So please don't do this.
I think the OP here was responding to the change in tone which signaled that such dry wit of response was “allowed” on such a post.
Had OPs comment not ended with some sort of puzzling naive phrasing and twist at the end, I doubt he would have felt comfortable with his dry cynical joke.
In some sense, he’s trying to cancel out the overly positive naive tone introduced by OP at the very end.
Equanimity and balance is not so bad. OPs weird ending belied a sort of youthful immaturity which struck counter to the wisened, aged tone with which he had cumulatively relayed with his story thus far.
The OP could have said "no thanks" and continued with his original order. Simple as that. It seems that your social cognitive circuitry is overloaded by someone acting like an actual person instead of a simple robot.