Running a web app with even over 10KLOC without some sort of framework in place sounds like a receipt for disaster. Also frameworks do not mean you have to have code generate all your queries or stick another templating language over php.
If you've never had to write or maintain a complex web application than I can understand your position but once you do I'm certain you'll change your mind.
Also saying web development is easy compared to other fields shows a lack of understanding of the complexity of large web based applications. I've worked in a number of fields and I now focus on web development and for the most part they were all about the same complexity.