It's because when you do RCs during the day you don't expect it to be a dream, youre doing it as routine without actually thinking about what you're doing. That's why in your dream, you think it's rediculous that your dreaming, cause you don't believe it could happen. When you do them during the day, think hard about whether it's a dream or not, and if it was, what would you do.
Another idea I thought of for people having the same trouble as you is to stop doing RCs completely. Don't do it during the day at all, and use RCs as a dreamsign. If you catch yourself doing an RC, it MUST be a dream, since you don't do it during the day, and you can become lucid like that
tell me what you think
~ike