This strikes me as very strange, in that materialism involves so many extraordinary claims that tend to be presented without any evidence at all.
For the sake of honesty, there are some caveats that should be added to that slogan, but it is true that wildly improbable claims should be supported. Still, those defending materialism are consistently forced into the position of making these claims:
1. Something can come from nothing
2. Applying logic to questions about God’s existence (i.e. metaphysics) is useless
3. The principles that are the basis of science (such as Ockham’s Razor) aren’t true
4. Having directly experienced a thing is no reason to think it exists
5. People are no more conscious than computers
6. People only think what we’re programmed to think, rationality is an illusion
7. A reason to think a thing can be dismissed with “I don’t know, and I’m okay with remaining ignorant”.
These claims seem pretty extraordinary to me. To the end that one agrees with the above mantra, one should demand an overwhelming amount of evidence before accepting that materialism (which requires these things) is true. And, given how much evidence there is against them, I’d say that it can’t be done.
In fact, any set of ideas this counter to the real world in which we live could only be called a (disturbing) fantasy world.
The fact remains, however, that most materialists seem very confused when I ask for support for materialism, and the kinds of things it leads to. It doesn’t seem to occur to many that it shouldn’t simply be the default position – true without evidence unless something else can be proved.
But if there is a position that should prompt us to ask for some support, surely, it is materialism.