Deadlines are not artificial. If you screw around long enough, various real world things happen, such as your competition leaving you in the dust, your product becoming irrelevant, customers not caring any more whether the problem is fixed because they've gone to a competitor. There are engineering realities, such as it won't be fixed until it's fixed. But there are business realities, too.

A formative moment for me was when I was the software manager for a company, and we had two clients with emergencies going on at the same time. The reality was, we couldn't really fix both problems at the same time. I went in to the president's office, and told her that we couldn't fix both problems right now, and I needed her to decide which client was going to suffer. She yelled at me, told me to get the hell out of her office, and figure out a solution that doesn't force either client to be the loser. I fumed and left, she obviously didn't understand the reality. But once I finished pouting, I realized there was a way I could implement a temporary fix for one real quick, and then work on the other...

There are business realities, and there are engineering realities. A business needs to manage both to deliver something awesome, or get overtaken by somebody else that will.