There are some great points made in this thread that I believe have a lot of truth to it.
1) The organization doesn't believe they can get in better coach - This is something I keep going back to; we have a good coach, and the desire to get a great coach is unrealistic. Marc Iavaroni would've been the coach if it wasn't for Nate. Mo Cheeks was coach before Nate. Nash/Patterson replaced Whitsit, then was replaced by an assistant in the organization looking to move up the ladder, and was again replaced by option 4/5/6 on their list. I'm pretty sure that Paul Allen and his crew's reputation around the league makes it near impossible to get a proven coach/GM.
2) Talent Issue > Coach Issue - This roster is horribly unbalanced and is thin at the two hardest and most important areas to fill; PG and C. Add in the fact that we are frequently among the league leaders in games missed due to injuries, and the deck has been stacked against us.
Nate isn't the best coach in the league, and he never will be. To me, going out and looking for a new coach would be like turning down $800,000 guaranteed to have a 50/50 chance at getting $1,000,000. Maybe I'm just risk adverse, but the odds don't appear to be in our favor.