I'm afraid I'd have to disagree with this idea.

Difficult content should be kept difficult. It was made that way on purpose to give a challenge.
To remove that challenge removes the purpose of that content.

You can think of Floors 1-100 as Alexander normal mode. It's really easy for just about anyone to do. (But still much easier than Alex normal.)
Floors 101 - 200 are Savage mode (as you said). So, it should be Savage. Why should it be any easier? If it were any easier to do, then it would just be like floors 1-100.

The rewards need to match the effort. I think things are fine just the way they are.

If people really want the mount, they need to be be willing to work with friends (or at least make a static of random people), and make the effort to obtain it.
Considering that floors 101-150 have been soloed by many people (and at least one person soloed to 160), it must be much easier to go past 150 in a group.
It just takes time, effort, and a little concentration.