Users: Great! Let's start using it everywhere!
Users: Hey! Our spreadsheets have become very slow and hackers break into our systems by executing arbitrary code in our spreadsheets
Microsoft: OK! From now on you will have to save workbooks that can execute arbitrary code in a dedicated file format, which will only open after showing 15 warning messages.
....
Microsoft: _Hey, we have this new feature. It's called Lambda. You can execute any code you like and use it as functions in your spreadsheets._