I believe that as an operating system provider, there is a duty to provide a minimum level of security and to ensure this is kept up to date. So when I get the security updates rolled out to my system, for me it is a no brainer and I expect these to be mandatory and I think they should be. Microsoft provides a platform and for business reasons, ethical reasons and more, they have to maintain a minimum standard of security. I am glad they do as they are sometime more responsible than third parties in rolling out updates to prevent a users PC from being infected.
I think the main issue between Microsoft and its users are the bigger "Service" updates. We all know that service updates come with both security and feature updates. I think the argument here is that it would be nice for these "Service" updates if you can choose to install only the security updates but not forced with the feature updates.
In an ideal world, I think people should be able to choose what features they have, some people like the way their system operates and do not want/require the facelift improvements. Features and security should be separate where possible. The only caveat to that is if you have a feature in windows that has a security flaw, sometimes the only way to properly roll out the security fix is for the feature to be fully updated. In these instances, it would be reasonable for Microsoft to force these types of feature updates when it is 100% required for security reasons.