Volvo to acquire Seven Marine; Outboard Engines...

This is not your father's Oldsmobile. That turned into the death of Oldsmobile. I think Volvo repeated the strategy. While it was a niche market, Seven had created a market for their product. Then Volvo acquired it and began talks of changes, using only part of the Seven product, whether as Capt J suggested or as you stated here. That's tearing apart, not building a brand. It's like many technology acquisitions where it's not really the company being bought but just some of it's technology. Sadly, they didn't buy Seven to build and improve Seven but to play with possible ways it might help Volvo. Well, it didn't, because Volvo has other issues and priorities to focus on. Sad that Seven gets lost in the process.

Did anybody (especially those shelling out big bucks for these novelties) not think that Volvo could be buying them just for the patents with intentions to kill the competition?

Yes, which was another step towards harnessing the massive torque of a diesel.

It's like when BMW bought Land Rover for their 4X4 tech and then sold it for just £1 after taking advantage of the situation for the X5/X3.