Going private is needed for Dell
For Dell to survive, they have to go private. It'll allow them to burn through a lot of middle management, shake up the company in terms of products and focus, and generally not be a loss leader anymore.
If sold to Icahn, there will be a payout to investors like himself, higher than what would be received by going private. The company would be put into more debt, and the company continue their downward spiral and will fail. Pieces of the business sold off and massive layoffs. More so then simply a management shake-up from going private.
So on one hand both scenarios get a payout to investors. However the greedy folks always want more. But only one of them will not involve taking on more debt to pay shareholders.