Unhelpful and ignorant.
Even if that were true (I'm not a doctor, and I suspect you're not either), would you say to someone with a broken leg to "get off those crutches, they're just a crutch"?
I took sertraline for a couple of years to help with stress/anxiety. For me, the effect was very subtle - there was no specific point where it "kicked in", but after a few weeks I just sort of became aware that I was feeling better without really noticing it. I didn't suffer any of the side...