Any theory which causes solipsism to seem just as likely an explanation for the phenomena it seeks to describe ought to be held in the utmost suspicion.
The quote from Iain M. Banks' "The Algebraist" suggests a cautionary perspective on theories that support solipsism, the idea that only one's own mind is certain to exist. When a theory can imply that the external world is merely a construct of our perceptions, it undermines the objectivity of scientific exploration. Such theories may lead to an unproductive or overly skeptical viewpoint that questions reality itself.
This skepticism can be detrimental, especially in fields that rely on shared realities and empirical evidence. Therefore, any theory that lends itself to solipsistic interpretations should be carefully examined. If it suggests that personal consciousness could be the only reliable source of knowledge, it may warrant distrust for its potential to derail genuine understanding of the universe and limit intellectual progress.