How important is a good rack?

I have a really nice turntable and some good equipment overall.

I have it sitting in a Michael Green just a rack., It's the entry level with the thinner shelves. I noticed it's not super sturdy if I bump into it it tends to wobble. If I am playing a record it skips. I have an older AR suspension turntable and I can walk all around the rack and it doesn't. I guess what I'm wondering does a rack need to be rigid?

Some rack suggestions would be appreciated. Thanks, Scott