Because just as in the world of law, car sales, and banking, there are bike shop owners who have no problem telling lies if they can make a buck. If they were running an art supply store, a head shop, or a shoe store, they'd be telling lies to anyone who they thought might believe them. Most often, a lie like this is followed by, "I can order you the part you need to make this work, but you'd still be stuck with old technology. What you really need is a new bike."