You are complaining about what gives you work...and you may be missing the point.
I came to consulting from industry having run several large businesses. There are several reasons why what you see as obvious may not have been tackled:
1. The management team is so busy fighting fires on a daily basis that they cannot see what is obvious - if you're fighting a fire you're blinded by smoke.
2. The management team may be split and situations are allowed to develop so that politics can play out - consultants are a wonderful judge and jury who's evidence can be leveraged to affect boardroom change.
3. Sometimes to be seen to effect major organisational change you let things slip a little, esp if new into a position as you can blame it on the previous regime and buy yourself time and a greater margin for comeback. Then, using your network and understanding you employ consultants to assist in defining your strategy (non exec boards and shareholders love the security of this) knowing full well what your strategy is before they even arrive.
4. Your management team is in fact sh"te and are lost and blaming each other.