More like a bountiful harvest. Even the dogshit programs windows users buy are mostly made with FOSS libraries.
The real answer is windows apologists don't want to hear Linux users gloating about how this never happened to linux, and how dogshit their beloved os is
Its about trusting the data you're decrypting actually came from who you think it came from.
So the data is signed with your public key, and your public key is published so people can verify the other stuff you publish. Your email is there just so people can communicate back to you...
You can of course put junk info in the fields if you want, but the purpose of the program is enabling trustworthy lines of communication.
It actually highlights the risk of having unaudited third party software running on your critical infrastructure