Straightline

The real problem was that having Jaguar in the family limited what a Lincoln could be. Lincoln can never be a world-beating luxury brand if every model they sell is a "Jaguar light".
 
Jaguar, in turn, was an "Aston Light".
 
Each step up in brands limited what the brand below it could be.

The problem with Jaguar was that Ford wasn't sure what they wanted to do with it. There was no vision.
'Do we make it a mass production Mercedes fighter or keep the upscale coachbuild mentality?'
'How do we differentiate between classy and old? Should be update the XJ?'
Ford did invest a lot of honest cash into Jaguar and did make significant engineering advances (V8s, aluminum chasses). But they needed to do more. Most car buyers don't care about power or weight. Style and bragging rights are more important in this category, and Jaguar had lost that (especially after the X-type).
 
Land Rover I think is bouncing back. I agree that this is the wrong time to sell. Tata is getting one helluva deal. Land Rover will be profitable in the near future.
 
Aston Martin was run properly in my opinion. They're very desirable cars. While I don't agree with the price (Ferrari level? please!), the product is alluring.

I still wonder why Ford and GM purchased ailing car companies in the first place as their own vehicle portfolio wasnt that competitive. Im guessing they were trying to outdo one another by being bigger. The "bigger is better" mentality just doesnt seem to work.