I find this argument deceptive in a number of ways. Firstly it's ignoring the quality and predictability of explanation for its propagation. Second, if the argument were true then we should see parallels in other areas of explanation where this happens. Finally, that it's a misdirection to cover up their own doctrinal commitments.
Triumph of explanation
Consider the following statement:
Atheists need to accept a heliocentric solar system because there are no natural explanations for a geocentric universe.Such a statement highlights the absurdity of what is being proposed. The reasons to support a heliocentric universe are because of the predictive success of modern scientific advancements in understanding gravitation and the observational data that a heliocentric model is able to explain. Scientists have used this model to land craft on Mars and send vessels to explore other worlds hundreds of millions of kilometres away.
The heliocentric model is the only realistic game in town, I say realistic because anyone could come up with a speculative suggestion about the nature of stars in the sky but we don't take seriously those stories. Evolution by natural selection is much the same, while there are many different possible explanations, it's the Darwinian paradigm that is the only realistic game in town. Not because it's the way to cast off God, but because it through empirical observation and analytic consideration is found to be able to explain life on this world.
Evolution by natural selection isn't the only game in town, but the only realistic one. Through an examination of the fossil record, the genetic code, geographic distribution and comparative anatomy. Through many different experiments on many different facets of biology, including on the addition and removal of various selective pressures. Through analytic contemplation of underlying philosophical considerations. Through all these the modern evolutionary synthesis has been deeply examined and has been found to be triumphant. It's the only realistic game in town for those reasons.
The cosmic competitors
Even if evolution by natural selection is the only game in town for good scientific and philosophical reasons, its propagation might be through atheists who don't understand a thing about it except that its a counter to the teleological argument. That is to say that the assumption that God made life as it is would be an incredibly powerful argument if not for Darwin's idea.
Yet the teleological argument doesn't only exist to explain life, but to explain the cosmos. The seemingly arbitrary values of a number of constants need to be so precise for life to exist that a personal intelligence would be the best explanation.
If this holds true that atheists are just grasping at whatever comes there way then we should see a uniformity in explanation - a tentative hypothesis billed as the only game in town. If there is one that can account for the universe that atheists default to, I can't for the life of me think of what it is. Of course my ignorance is not an argument against there being one but I'd actually be surprised if atheists in general really had sufficient knowledge of cosmology to be able to even comment on the assertion's coherence.
But why does it actually matter? The validity of evolution stands with the evidence for it and the issue is one big red herring. If I were to argue that astrology was nonsense because my magic 8-ball says it's crap, the problems of astrology persist irrespective of my reasoning for it. While my personal attack on astrology would be absurd, the discipline of astrology is neither strengthened or weakened by my argument.
My real rejection of astrology, however, comes from an understanding of what planets and stars are. I reject it because constellations are an artefact of our current position in space-time and there's nothing we know that could even suggest a link between the relative position of planets and stars with events in our lives. We can navigate by constellations, start wars on the position of Mars, but that's not the causal relationship needed for astrology to be valid - it's just us finding a pattern (that's not there) and acting upon it.
When people make a doctrinal commitment to the inerrancy of The Bible and that commitment leads to rejection of any contrary information, then a rejection of evolution can be said to be done out of necessity. Likewise, when those who are crusading not for creationism but to get more people to Christianity could be said to arguing against evolution out of necessity. After all if evolution makes God unnecessary then it's taking away a strong reason to believe. Indeed this is what the Wedge Strategy, just like so many other attacks on evolution indicate, spelled out. Evolution is just the tip of the iceberg in the larger culture wars.
This is why I think that such arguments are projections. There was nothing in declaring myself an atheist to make a commitment to evolution by natural selection. There are atheists who don't think that natural selection works, or that it's insufficient to explain life. The charge of the only game in town is trying to put the focus of doctrinal commitment away from those who have one.