OSS: We don't support .NET 4.0.
Company: We run a billion dollar line of business and have to run on .NET 4.0 because that decision is made above me.
OSS: Point me to a contribution you've made to any OSS in last month and I will patch.
Probably a healthier response would have been "Send me your economic buyer; we'll talk."
The person at a company with authority to approve the purchase of your software license / consulting gig / etc you're going to pitch. Generally not the dev looking at Github in a billion dollar business.
Nothing to talk about; you wouldn't propose marriage to someone through their cat.