Figuring out "why now?" implies you understand and can verbalize the exact spot an industry is in. This wil take you at least 4 years of working in hat industry. Infact I would go so far as to say it's nearly impossible to answer the question "why now" without creating a product or working in that industry. "build something people want" is a much better tactic than making decisions based on an answer to this question which in all essence is a thought experiment of dubious value.