Hard to say what part of the shortfall has to do with management, but the basic numbers I'm seeing from this example is that 90k units sold with a development team of 20 personnel over (don't know the development time) a presumed 1-2 years is not enough to keep a development studio in business developing for the Wii. Unless they actually started development in 2006, which would go a long way in explaining the shortfall.
Of course one has to take into account that it was a new studio, with no prior releases which meant going through the lengthy process of setting up all resources and libraries using teams that presumably had little or no former experience working together.
The most unfortunate part is that stories like this do not bode well for small studios making attempts to produce unique, smaller niche titles, which means higher odds of seeing low cost party titles and fewer games like Cursed Mountain.