@Slashscreen You can add another column to fill in the extra space, or get a browser extension like Stylish with the Variable Width theme to resize the columns to fit your browser window.
@Slashscreen Personally I like having all the columns (multitasking wooo~) but I understand that for some people it makes the screen feel too busy, especially when the timelines start moving quickly.
@Slashscreen Then it makes sense that you wouldn't want to use a UI that is VERY similar to TweetDeck haha. Totally fair, and you're not alone. That's why people make alternate interfaces :)