[rmc]

You're using the "Tone Argument" derailing technique: http://www.derailingfordummies.com/complete.html#angry

Try to see what she's angry about first. Sometimes people are angry at what they think are gross injustices. Maybe she has a point.

[JasonFruit]

Sometimes inappropriate tone can turn people off of a discussion. That's one of the perks of reading; if you don't care to be shouted at, you can stop reading. Presenting what you think in a way that makes people want to keep reading is important, and failing to do that lost her a reader.

[rmc]

Sometimes. But sometimes it's used as an excuse to not listen to someone. Sometimes no-matter how valid someone's point is, some people always find and excuse to derail the conversation (look at that long list). So not matter what you do, you always lose. Sometimes one gets tired of that.