There is a couple of reasons. First, VP is essentially just putting code snippets into nicely coloured boxes, which adds no value apart from making you have to scroll/zoom more. Additionally the structure of the visual becomes important, opposed to text which can be infinitely appended to, and so once you add enough complexity the whole thing becomes complete spaghetti.
VP also hides away a lot of implementation details from you, and assumes the computer will be able to figure out something better than the programmer. For example, when would the dropdown run the SQL query? on page load? on drop down open? As you scale the app bigger, you may want to run a single SQL query and then chop up the results and hand them out to several dropdowns. If your VP interface doesn't support this then your done for, but with code there is always a way.
There is always Clojure of course, which lets you edit your GUI while the app is running, and upload code changes without having to rebuild, allowing you to tweak stuff as you go. REPL driven development is great as it gives you both the flexibility of written code, as well having close to the interactivity that VP offers.
>> For example, when would the dropdown run the SQL query? on page load? on drop down open?
You seem to be dancing around what I came to comment on, and that is event driven programming. It's OK for simple UIs but it tends to break down as complexity increases.
VP also hides away a lot of implementation details from you, and assumes the computer will be able to figure out something better than the programmer. For example, when would the dropdown run the SQL query? on page load? on drop down open? As you scale the app bigger, you may want to run a single SQL query and then chop up the results and hand them out to several dropdowns. If your VP interface doesn't support this then your done for, but with code there is always a way.
There is always Clojure of course, which lets you edit your GUI while the app is running, and upload code changes without having to rebuild, allowing you to tweak stuff as you go. REPL driven development is great as it gives you both the flexibility of written code, as well having close to the interactivity that VP offers.