That's the problem with your thinking and people like you in this thread: you're entirely banking on faith that IBM won't ruin RH, even when you cite a great example here about Oracle making similar acquisitions and running them into the ground. Seriously, what makes you think IBM is going to be any different?
I'm just trying to be optimistic in this case, although I agree with how acquisitions always run into the ground regardless of the company, but something tells me IBM would think twice about doing something remotely like that to RH. For one thing, they contribute excellent work into the kernel and some of their senior engineers have had pivotal roles in adding components to the kernel which may have been a significant factor in improving it, and a minor testament that they care about the system as a whole. That doesn't guarantee anything but it is quite evident from their perspective that they are just looking to both increase their foothold in the industry and improve the base system.