I will tell you my own personal experience.
Back in those days working with classic ASP, a new emerging product was creeping onto the market, amazingly it was called "ASP+", this later turned out to be ASP.net.
ASP.net brought a lot of new functionality to the world of CGI Scripting. Remember before ASP.net in the Microsoft World it was impossible to develop against OOP.
So along comes ASP.net introducing new languages VB.net and C# - the others have pretty much dropped off J#, etc. Strongly typed OOP languages.
Another important step forward was the revolutionary way ASP.net allowed you to code stuff like button onclick events, as if you were coding a windows forms app.
I think that was part of the original concept - to have a web programming environment that was easier to manage and debug.
Before ASP.net - debugging was very much hit or miss. ASP.net did a lot for the scene.
All in all, the technology is not perfect I know, and ASP.net can still be a bit messy, without hard edges between tiers, but it still deserves credit as possibly the best revolution the web programming world has ever been.