Writing -- even in a business setting -- is hard work. After we write something, we are reluctant to delete it. It almost seems nonsensical, why would you delete something you wrote? You spent time writing it! You chose each word, you typed it, proofed it... Why would you delete it?
That thing you wrote might have been the best phrase, sentence, paragraph, or page that you have EVER written. But if you review that email, report, proposal, etc., and realize that section is not necessary information, take it OUT. If your reader doesn't need it, you should delete it.
If you're proud of it, you should honor that feeling. Save that [sentence, paragraph, page] in a folder, print it out and admire it, send it to your mom or send it to yourself. But if your reader doesn't need whatever it is you typed up, you should delete it from that document.