Obligatory car analogy: Would you like it if you took your car in for blown head gasket and they tried to up sell you on a paint job or new tires?
The problem isn't so much that the sales people are trying to make sales(it's what they do), it is that the customer service and tech support is being recruited for that too. If I am calling support for something that means they have failed to deliver on my existing service(billing or technical). That is not when I want to be asked about upgrading a currently unsatisfactory product. And having to barrel through a sales speech just to get a problem fixed is not something anyone should have to put up with, any other industry with true competitors would have them drummed out of business with that level of customer care.