I think they consider sound money to not provide an easy enough lending environment. If the money goes up in value than there won't be enough incentive to invest, and society will grow too slowly or decay.

They don't see money and prices as information; they see money as wealth and prices as a bad thing, rather than money as economic energy and prices as the information that individuals (neurons) process to coordinate economic activity. Interference in the price of money is like your brain on hard drugs, no longer able to properly respond to the stimuli provided by prices.

When lending is tight, that's simply a sign that the economic brain has determined the market is awash with bad investments and storing energy is of more value than lending. Instead, Keynesians think these economic tumbors should be protected.