Because it doesn't work very well. I have found that it works "sometimes" and with "some" controls. Others? Not so well. For example, if I wanted to edit the background of the RadMenu using that tool (vs. raw CSS) it just doesn't render the settings I'm entering-- but if I change them in raw CSS-- voila! try this:
Go to the URL you provided
- Select "New Skin"
- Select ASP.NET AJAX (the default selection)
- Enter "TestSkin1" for the name
- Use "Default" as the base skin selection
- Select the RadMenu control (only that control)
- Click Create
- Select the "Fine Tune" tab
- When the menu displays, click on "Expandable/Expanded"
- On the bottom area, change the Position value from -216px to -200px and press tab
- Click on the "Expanded (outer wrapper)" tab
- Click on the "Expandable (only inner)" tab
- Change that same value back from -200px to -216px
Note how the menu DOES NOT restore its appearance to what was rendered on load (since you just changed it back to load time values). Like I said before-- that tool is hit and miss. Especially when you change browsers.
Anyhoo, I solved my problem using raw CSS.
However, to anyone trying to learn Telerik components and skins (I've been using them for 7+ years), I highly recommend you use that tool as a learning tool. how? Simple. Load up the CSS/Skin/graphics on your local machine, then go to the online tool on another screen and tune the values you want to work with. Then download the Zip file and use a tool like CompareIt to compare the differences between the two files. Like this you can learn what you need to change without having to be connected to the internet everytime.
Oh, and Telerik, if you're listening, what would make that tool really cool is if you could click on elements, identify the value you wish to change (e.g., expand arrows, like in the above steps) and then highlight where in the CSS file we need to make the change. Like this, you show us on screen what to change, we get to change it in VS and we learn how to be self sufficient all at the same time. This saves the steps of packaging, downloading, unzipping and copying to directories as well.