Why has the menu changed. I don't like the new menu structure and I want the old menu structure back.

I can see that you're more comfortable using the old menu option, user06667.

Changes to the options are coming from our requested customer's feedback/suggestions. 

Your feedback goes directly to our product developers to help improve your QBO experience.

You may visit our updates page to discover the latest innovations and product enhancements.

Get back to the Community if you have any other concerns while doing tasks in your account. We're always ready to help.

Try clicking on the gear at top, and then on the lower right, there might be an option that says "Switch to accountant view." If you have that, you're lucky enough to go back to the way it should be! 

I too was furious about this new change. Its awful and distracting. However I JUST found something that made it a bit more bearable (maybe it will help others too)....
If you edit the menu and add your most frequently visited tabs as a "bookmark" (Mine were Banking, Reports, Reconcile and COA) Then when you click on one of those bookmarks (as opposed to clicking through the menu levels) then the menu stays open and doesn't collapse and do its annoying animation. Just thought I'd pass along to others who have been struggling like I have with this menu redesign.