The long road of our industry is littered with the corpses of projects which would only take a few programmers a couple of weeks to program. But technical risk isn't the big worry here for a startup.

Hell, someone should do it here, would be a decent startup idea, copy them, but charge $29.99/$59.99/$99.99 for your plans.

That hypothetical startup would be:

a) Trying to market the product without having a successful reference implementation available and without having Joel & Jeff to bootstrap the reference implementation.

b) Be aimed squarely at the low end of the market. (i.e. penny-pinching pathological customers rather than enterprises for whom $1,000 is inconsequentially cheap if it brings projects in on time) This buys you some very fun customer support duties.

c) Need to sell minimally several dozen companies on a quirky knowledge-base type product per FTE they wanted to support.

d) Get to compete on search advertising with someone who can afford to outspend them ten-to-one for customer acquisition.