The poster is not questioning the need for open standards, they are questioning the user's need to have that particular standard implemented in hotmail.
He wasn't just questioning that particular standard. He was completely unable to understand a user wanting it. He had no clue that there is so much software out there that works with IMAP, but doesn't work with their proprietary protocol.
When I saw that they mentioned ActiveSync, all I could think of was "I'd have to plug my phone into my computer to get email???" I didn't know that's what they call their push service now.
Which is not necessarily a bad thing to do IMO.