new look in firefox really is terrible. Like others complaining, I might as well use some other browser because firefox now sucks

I want my old Firefox look back! What the heck have you people done and why. Does someone else now own Firefox? I loved it before and now I'm so aggravated I will look at other browsers and even if they are as bad as this "new look" in Firefox, I will switch anyway! Why the heck did you do this and who's brilliant idea ruined my Firefox?