Without Microsoft, Novell would have hit this crossroad many years ago. Novell could not have slowly and organically built a Linux business fast enough to replace lost revenue from the decline in things like NetWare. Microsoft gave them cash, marketshare, and mindshare (with paying enterprises, not the FOSS community of course).
Indeed, the Linux business of Novell has steadily increased and is one of the bright spots if they are allowed to continue. But it is doubtful that an investment firm is going to be interested in slow but steady, long-term growth when they can gut the company and make a quick buck.
Novell may ultimately fail, but they have already made it much further with Microsoft then they would have without.