The only reason why you would think this, is if you didn't understand how to use it. Not to offend you, sorry if I did.
The difference between TWC and CORE is that core allows you a one to one relationship, vs TWC relationship system.
To explain through examples: CORE allows you to drag a single widget instance to a single sidebar. TWC allows you to not only assign a single widget to a single sidebar, but it then allows you to decide which pages that you would like that widget instance to either display on, or hide on.
Meaning that with TWC you now have control over which widgets display on which pages. Have a look at the edit page, see here that you can check off which pages that you want this calendar to be viewable on, on all other pages this calendar will be hidden. http://screencast.com/t/PWc3qC1tlpdq
See that I can also choose to have a widget display to only a specific category page, or to all posts within that category.
I hope this helps.