The Katz era has not been all that bad when you consider that there was a purposeful scorched earth rebuild done for the benefit of the team, and was done so at a high amount of financial risk. I think most fans were behind it at the time, and the patience has only started running out in the past couple years. In this time, we have clearly been in the part of the rebuild where we should start seeing results but shouldn't. However, 2 years is not a lot of time, but once things start going sour many fans start counting every year since 2006 into that equation.
So far, I view the Katz era so far as a good thing considering the talent we've accumulated. There was a speed bump where he decided to wait out a rough patch a bit, but to me that's more of a testament to him not wanting to make kneejerk decisions with such a fragile group, which is reasonable. It also gave Chiarelli a lot more pieces to work with. Overall, since the rebuild was started in 2009-10 (really 2010), if we start seeing real results now that would be a 5 year rebuild. That's not so awful.
Also, for us it can seem so easy to replace a GM and President, but it really isn't. There's a reason why 'Old Boys Clubs' pop up all over the league. There's only so much you can learn from interviews, and it makes more sense to stick with what you know rather than what's random. Katz realized this was a problem so he hired Nicholson specifically for his connections. Even that hire had to have the right opportunity though.