I'm a little taken aback at your vitriol. Is "Stifled other libraries" a synonym for "Does the job well enough that nothing else was able to compete" ? That's been my sense. A lingua franca for graph visualization, pervasively available.

I hardly think they'd turn away algorithmic contributions, if you've got some.

Do you have an example of your hideous bow ties? I don't usually use graphviz to 'draw' anything, so I don't really have the context to understand your complaint. I've never seen a result I think of as a hideous bow tie.