Don't be too harsh on Grok/Dexterity. Dexterity has worked out how not to repeat the definitions in interfaces, forms and content objects. It also produces an application with suprisingly little redundant code. I urge you to try it out. The benefits are of course quick turn around, version control, testability and the debugger.
Also note that (the Plone integration for) Dexterity allows you to create
types entirely through-the-web. This can then be meaningfully transitioned to filesystem development without forcing you to start from scratch. The big, big problem with any kind of TTW development is that it usually breaks down badly when you move your code to a production server and then need to continue development in a separate environment. Code and configuration stored in a database is difficult to deploy and merge when the same database holds live data and content. The same problem exists where more than one developer needs to collaborate. Without source files and source control, it's impossible to give each developer their own sandbox. Martin