Not sure I get your meaning.
In a universe where things have causes and not purposes, there's no reason to believe that "memes that promote survival/reproduction survive with the most success".
The original idea behind the meme model was that ideas perpetuate kind of like pseudo-lifeforms whose niche is the human mind. Starting there, there isn't really any reason to assume they'll be any more beneficial than the pseudo-lifeforms whose niche is the human body: Viruses. Sure, like with viruses, a meme that kills its host or makes him an outcast before it can reproduce is unlikely to succeed, but that's about as much as it "cares" for our wellbeing. Whether a meme spreads is more determined by easily it is transmitted than by its net cost/benefit to the carrier - and the ease of transmission in turn is determined by a variety of factors from innate cognitive biases, via how much it is compatible with experienced objective reality (or appears to help understand reality), mediated of course by how our senses perceive said reality, to how well it fits in with other memes present in that environment. A meme that makes everyone it infects commit suicide on the spot is unlikely to spread far, one who makes them spend a very substantial amount of their time and money on proselytising very well might.
You seem to be insinuating that uncritical thinking is encouraged by evolution because the memes that survive will be most beneficial ones, and they rely on uncritical thinkers to spread. You might as well say indiscriminate copying of DNA is encouraged by evolution because viruses serve the good of the species. In both cases, we're more talking about an unavoidable consequence: viruses/memes evolve too quickly to build hard-coded defenses, so all our best efforts at fending them off will sometimes fail - and the mechanisms they use to reproduce are too vital to turn them off altogether.
I'm not actually bought on the idea that the meme model is particularly good at offering an understanding of cultural evolution.
But it deserves better than to be abused as an excuse for resurrecting God/telos.