I agree that while CS did screw up in pushing out a bad update, only having a single vendor for a critical process that can take the whole business down is equally a screw up. Ideally companies should have had CS installed on half the systems and a secondary malware prevention system on every DR and “redundant” system. Having all of a company’s eggs in a single basket is very bad.
All the above being said; to properly implement a fully redundant, to the vendor level, system would require either double the support team, or a massive development effort to tie the management of the systems together. Either way, that is going to be very expensive. The point being: Reducing the budget of IT departments will further cause the consolidation of vendors and increase the number of vendor caused complete outage events.