Scale is not currently supported in history based modeling. There is an option to create designs that not capture design history which provides the tools that are not supported in history capture mode.
You can create models without parameters or history by changing your preference for new file creation to "Prompt" which will ask each time you create a file, or "Do not capture design history". I prefer the "prompt" option because I make models with and without capturing history/parameters. It's nice to have a choice up front.
Go to the three bar menu (upper left) > General > Fusion 360 > Design History to make this change.
Also, if you have started a design and wish to switch to capture or not capture design history, right clicking the top node of the model browser shows a menu with the option to switch to the opposite mode. "Capture Design History/Do not capture Design History"
Thanks,
Phil Eichmiller
Software Engineer
Quality Assurance
Autodesk, Inc.