So I've been trying to think about this rationally today, trying to figure out why Ole is still in the job when his position is frankly untenable, and this is all I've got.
The options available to the board are thus:
Option 1: Sack Ole, pay him off, recruit a new manager and hope he makes top four. The risk here is buying out Ole's contract (somewhere in the region of 20 million) in addition to the even greater cost of missing out on CL football next season. The board could be looking at approx.50 to 60 million in losses should the new manager fail to make top four, which has the knock-on effect of reducing appeal in the transfer market and to a potential new manager.
Option 2: Keep faith in Ole, believing he can turn it around and qualify for the CL. The risk: virtually zero. The board knows the squad is good enough to finish in the top four despite the manager potentially holding them back, which they have managed to do two years in succession. They'd also save themselves the embarrassment of sacking a manager they very recently gave a new contact.
It's a risk either way for the board, but I think they've gone with option two because it is by far the most cost-effective solution - at least for the time being anyway. If a new manager becomes available who can all but guarantee a top-four finish, they'll go with option 1.
Bear in mind this is just my opinion, in no way related to fact.
TLDR; it's all about the money. Ya know, just in case you need confirmation of that. Which you probably didn't.