Lean Startup Canvas: the wrong tool for Tech Ventures (create-build-execute.com)

a canvas helps to structure ideas and directions. the canvas is just a snapshot of a product, and there are a number of different canvasses out there. for example, the pain/gains/job canvas, which I tried to apply to freelance projects: http://thinkingonthinking.com/customers-jobs/ - what could be wrong with this?