IMO, there was nothing horribly wrong with WebForms itself when it was introduced -- So long as you were writing your HTML by hand and using HtmlControls rather than the drag-n-drop stuff.

ViewState was far better than other frameworks that shoved the client state into a server session object and broke the Back button. Plus the clients were saving state instead of wasting server memory. If it got too ugly, you didn't even have to use it, the http variables were still there.

Remember this was all designed back when Netscape 4 was a popular browser and any Javascript was considered exotic. Of course we have much better way to do things now, the WebForm approach broke down hard as soon as it encountered AJAX. But originally it was fine.