I think the point is "If you cannot espouse the benefits and possible market of the product you yourself are building - why are you building it?" Basically -

I think the point is "If you cannot espouse the benefits and possible market of the product you yourself are building - why are you building it?" Basically - be your own advocate. If you can't handle someone asking about your product (even in a negative fashion) how the hell can you hope to have the conviction and drive to actually sell it? You don't need to "convince" every critic - but you sure as hell need to be able to step into the ring and talk to their points. This is the same reason debate teams often explicitly spend time reviewing the problem from their opponents perspective - you must be able to understand and counter arguments from your detractors.