my point is that it is a derogatory abbreviation commonly used by people who, in fact, do not have an unbiased view of Microsoft. it's harder to type than just

my point is that it is a derogatory abbreviation commonly used by people who, in fact, do not have an unbiased view of Microsoft. it's harder to type than just "MS" so when someone uses "M$" they go out of their way to signal that they are biased. Being biased is fine, so long as one understands that they are biased and that they are communicating their bias along with the rest of the message.