I accept all the argument for why one should be an effective altruist, and yet I am not, personally, an EA. This post gives a pretty good avenue for explaining how and why. I'm in Daniel's position up through chunk 4, and reach the state of mind where

everything is his problem. The only reason he's not dropping everything to work on ALS is because there are far too many things to do first.

and find it literally unbearable. All of a sudden, it's clear that to be a good person is to accept the weight of the world on your shoulders. This is where my path diverges; EA says "OK, then, that's what I'll do, as best I can"; from my perspective, it's swallowing the bullet. At this point, your modus ponens is my modus tollens; I can't deal with what the argument would require of me, so I reject the premise. I concluded that I am not a good person and won't be for the foreseeable future, and limited myself to the weight of my chosen community and narrowly-defined ingroup.

I don't think you're wrong to try to convert people to EA. It does bear remembering, though, that not everyone is equipped to deal with this outlook, and some people will find that trying to shut up and multiply is lastingly unpleasant, such that an altruistic outlook becomes significantly aversive.