"I used to be really easy, always happy and always laid back as an 8-5'er working for the 'man,' but now I realize I have actually become sort of an asshole. Unfortunately, the realities of business make you that way. And you really have to be an asshole to be successful."
I've heard the same thing from a lot of entrepreneurs and I've sensed it happening to myself as I've gotten more aggressive about pursuing my goals. I'm pretty sure I'm happier, or at least more fulfilled, but sometimes it sucks having to replace that lightheartedness with grim determination.
That part's not true. You may have to be in some areas of business, including perhaps the world of $20k software, but I know plenty of successful people who aren't assholes.
You do definitely have to be determined. But determination doesn't imply being an asshole.
The customers make decisions in terms of things like keeping up with competitors ("we have to upgrade because they did"), and risk to their personal careers ("I dont want to rock the boat"), and compliance with industry standards/buzzwords ("Your competitor supports XYZ, why don't you?")
They want to hear that your software is scalable, easy to use, secure, and well-designed, but they don't actually care if it is or not, and won't even check.
If I had to sell a product that had sub-standard usability or UI response times, I'd feel like an asshole. To others, its just how you do business.
Then don't.
Excellent usability and response time are minimum requirements for any software.