MacArthur kind of exemplifies the damned if you do, damned if you don't predicament the Catholic Church faces. If I'm thinking of the right guy, MacArthur also lambasted the Church based on his understanding of extra Ecclesiam nulla salus.
As to his specific objection, the Church allows for the possibility for salvation of those with invincible ignorance of Our Lord. If their life circumstances prevent them from hearing the gospel, these might still be saved. And if such a thing is possible, Christ will still be the one who saves them. Explicit faith in Him simply won't be the catalyst of salvation in these special cases. But their Savior remains the only name given under Heaven by which we might be saved.