"Uhh, hate to break it to you but startups don't get "special valuations" because someone calls them startups."

Is this condescending tone necessary?

I was suggesting growth plays a large role in why startups are valued differently than established businesses, and I don't see how you can argue that a rapid growth company will be valued according to the same metrics as a company with very low growth.

> And, it is irrational to compare startup valuations to established companies. They're not the same category.

Is it necessary to be so matter-of-fact and imply that people aren't being rational (and thus inferior to your clearly rational point of view ). You're not wrong, the tone isn't necessary but I guess I was just following your lead.

You're not wrong about that, it was more dismissive than it should have been, though I'm not sure how else to express the idea I had in mind. Perhaps I should have instead said something along the lines of, "I value rapid growth startup companies very differently from established slow-growing companies." without expressing an opinion on whether that's reasonable or not. I'd guess everyone here can make an assessment about how growth is factored into company valuations.

I'm not aware of any connotation of "matter-of-fact" meaning "rude".