I heard this from management over and over again during my engineering career.
It never occurred to them that nothing gets sold until something get's built. They took this part for granted.
The more pertinent question is why does American business culture emphasize and reward sales more than engineering?
In other words, how do you logically explain why the guy who sells the product gets a share of the revenue but the guy who built it doesn't?
They shouldn't hate salespeople since without them they would most likely not have a job and vice versa.
Another reason: most engineering workers aren't given revenue sharing bonuses, but sales people are for selling the product of the engineering team's work, which breeds resentment. (A little like a line cook resenting tips given to a server, if not shared with the kitchen.)
Speaking personally, I hate salespeople because they're always selling me something. Engineers, by-and-large, hate salespeople because the self-actualization of a salesperson is worthless. The best salespeople are typically the worst people. The best engineers (Woz, Ritchie, Lattner) can make a positive impact even in-spite of commercial interests.
She left for Interwoven. In the meantime, I handled most of two jobs, with sales reps flying up from L.A. to help. We worked one major proposal for a college library that was pretty cool but never flew. Had some great customer meetings. The customer knew a great sushi place nearby. (No, it wasn't all about food. I wrote some great proposals.)
Got a rookie sales person who knew jack (lower case j) and came to customer meetings unprepared. Majorly pissed off a major customer by suggesting that they rip out all their servers and replace them. It was hell.
I joined a startup with another Sun person who was so sales oriented that he promised the world on a platter. Guess who had to deliver? Well, it all fell apart. I was so confused as scope increased and the crew was reduced in order of competence. Competent first.
I forgot simple things (rsync is a gift from the Gods) in the madness.
I sure missed the salad days (even if the salad was Jamba Juice).
But I have learned to be wary of them. They have a tendency to misrepresent the products to one degree or another, make promises that engineering can't fulfill, and that sort of thing. They can make my job more difficult as a result, so they have to be watched carefully.
But I've worked with a number of great sales people and teams, who actually care about improving customers' lives with our products.
Our collaborations have been great because they're a fountain of insight into how customers view and use our products, which helps us streamline existing products and come up with new and better ones. It becomes a virtuous cycle.
Without them, you're stuck in a "better mousetrap" problem.