For those that can't see the need to appoint the right person quickly...
We have already proven that taking a long time and doing the due diligence does not necessarily result in a good decision.
Let's say that we appoint someone in 2 weeks time, as suggested.
1. The world cup will have started - which generally means a slow transfer market, especially for top players - the ones we should be looking at.
2. The poor guy will have no insight into the remnants of our squad. He'll be able to take advice, but won't know for himself, the roles that need to be filled - I'm not talking about positions more captains, free kick takers, etc. He won't have deep knowledge of the attributes of those remaining - pace, power, heading, etc.
3. Only at this point will we have a good idea on formation of the team and the recruitment priorities - even the obvious, full backs... or maybe wing backs?
4. There will be 2 weeks to sort out everything before pre-season starts. From who does what in the coaching dept to where to live.
5. There will be 4 weeks until the 1st preseason friendly, and by then we need to have a full team - every position.
6. There will be 8 weeks until the 1st game to bring together this group of strangers, and coach and drill them into a coherent team and win PL games.
This is not ideal. It makes success less likely. It puts us at a disadvantage - in terms of player recruitment (right now) and implementing systems and tactics once the season starts (with the players that are eventually bought in).
It could all be done so much better and more effectively.
The team that has finished 17th has been relegated the following season in 3 out of the last 4 years. Therefore, we have to make a really good job of this massive change we are undergoing.