Try working in support for a while. Customers only call when something isn't working the way they expect, and since documentation is usually and afterthought among development teams, figuring out what is really possible with the software is often difficult. When you do identify bugs, you often have to go back to the customer to tell them it's not going to be fixed - and take the abuse that comes with those messages. Let's not even talk about non-technical salespeople who may not really know what the product is capable of and either tell customers wrong things or outright lie about what the product can do to make a sale. At which point, once again, the problems end up in the laps of support engineers.