Pitching is not the be-all-end-all, and you'll certainly get to a point where it stops being so useful for you (i.e. if you've already determined the reasons why certain people aren't interested in your product, no need to pitch them). We're not advocating pitching for the sake of pitching, we're advocating being methodical about and maximizing your learning from your pitches.
For example, biases will definitely crop up when you pitch people. They will also crop up when you go to try to acquire customers or deal with users, so it's good practice to field them early on. Going outside your normal circles will expose you to people who aren't your friends just trying to be nice or "experts" who think they know it all and that your product sucks, so that you can 1) sharpen your own communication skills (you'd be surprised how many startups suck at describing what they do), and 2) refine your understanding of customer concerns.
Also, pitching is just the beginning of validating your idea. For example, if you get people who sound excited and say they'll pay for your product, and then they don't, there can be a number of causes: 1) Maybe they were just being nice, 2) Maybe your product doesn't meet their expectations, 3) Maybe they changed their minds, etc. If you don't pitch these people, you don't have the opportunity to develop the customer insights you can get once they take a harder look at your product.
In the event that someone listens to your pitch and is totally disinterested, this can be valuable too. It may be that the person you thought was a potential customer actually isn't - I'd dig deeper to find out why. Maybe you just need to explain it a different way, or catch them at a better time.
For example, biases will definitely crop up when you pitch people. They will also crop up when you go to try to acquire customers or deal with users, so it's good practice to field them early on. Going outside your normal circles will expose you to people who aren't your friends just trying to be nice or "experts" who think they know it all and that your product sucks, so that you can 1) sharpen your own communication skills (you'd be surprised how many startups suck at describing what they do), and 2) refine your understanding of customer concerns.
Also, pitching is just the beginning of validating your idea. For example, if you get people who sound excited and say they'll pay for your product, and then they don't, there can be a number of causes: 1) Maybe they were just being nice, 2) Maybe your product doesn't meet their expectations, 3) Maybe they changed their minds, etc. If you don't pitch these people, you don't have the opportunity to develop the customer insights you can get once they take a harder look at your product.
In the event that someone listens to your pitch and is totally disinterested, this can be valuable too. It may be that the person you thought was a potential customer actually isn't - I'd dig deeper to find out why. Maybe you just need to explain it a different way, or catch them at a better time.