As I illustrated in my reply there.

Your CIO/CTO/whatever might not be interested in the long term benefit to the company.

Going with MS might be the "right" decision for his/her agenda.

Don't forget that everyone "needs" to have seemless compatibility with .doc and .xls files.

Migration isn't easy. Unless you never deal with the outside world or are so huge (like a government) that you can set your own standards.

But because it isn't easy does not mean that you shouldn't be taking steps to accomplish it.

Spend a 10% of your MS budget on non-MS training / evaluation / development / deployment.

Identify the roadblocks to migration.

Migrate what you can, as soon as you can.

Don't dig yourself in any deeper unless there really is no other option.

And remember, unless you're the decision maker, there are probably agendas you aren't aware of that will impact this decision.

And lastly, you can always move to a company that is more inline with your views. I did.