Can an audio rack be that important?

Not unlike a good speaker stand - solidity, stability, mass, and damping.  Give your equipment stable, solid, damped support and let your choice of footers and mass loading do the rest.  
I use a combination of very solid and heavy wood furniture, and a Sound Anchors steel stand that is sand-filled for damping, and supported on elastomeric footers.

If I had a bunch of money to spend, one ot these would be nice.

Solidity, stability, mass, and damping - you don’t need to spend a lot.

Thanks guys. 
Prioritizing spending on what makes the most sonic difference can be part of the fun.  I have always tried building or configuring stuff myself like different types of stands, air bladder suspension, lots of cables, and the damped springs I use as footers beneath Sound Anchors speaker stands.   
I try not to get too hung up on the need to spend lots of money to accomplish a goal. For example, a little effort and ingenuity could turn a typical block equipment stand or a flexy stand into something with a unique look.  The stands in the previous post are a good example of how you can make something cool without spending too much. Below are some shelves we recently added as part of a renovation in one of our offices.  The combination of steel framing and aged/cured hardwood boards looks great, and could make a really cool equipment rack, but unfortunately the wood was not cheap.

Yes indeed, the Fleetwood Rack is hugely expensive. I am sure it meets my rack performance goals, but the reality is that folks buy it for the cool factor and the OMA/Fleetwood clientele consist of folks for whom money is not the main issue.

My Sound Anchors stand also meets my rack goals and while not cast iron, it is steel, can be sand filled for damping, and can use wood shelves with elastomers under them (like the Fleetwood) if the owner desires, at about one-third the cost. There are many examples of wood and/or metal stands at a wide range of prices that offer solidity, stability, mass, and damping.

To the OP’s question, I find his subjective quality characterizations interesting:

• a good audio rack
• ultra high end audio equipment
• sub-par equipment racks
• a high end audio rack
• a reference rack
• high quality components

These types of subjective quality modifiers have been used widely throughout these forums, and throughout this thread, and I often wonder what level of correlation exists between the meaning of these phrases when used by various authors.

In this case of audio racks, I am interested in what physical/mechanical characteristics take an audio rack from the realm of being sub-par or basic to being good, high-quality, or reference? Racks costing thousands of dollars are made by a variety of manufacturers, from a variety of materials, using a variety of assembly and support methods. What makes an audio equipment rack good?

@audiopoint 

Regarding your list of answers to my question:

what physical/mechanical characteristics take an audio rack from the realm of being sub-par or basic to being good, high-quality, or reference? 

• Nos. 1,2, and 3 are important and desirable.
• No. 4 is claimed by just about all designers.
• No. 5 is a design goal that is attempted by most using a variety of methods and materials, including the structure itself, shelves/supports, elastomeric supports, and footers.  Unfortunately, the level of achievement of this goal is near impossible to show between designers/manufacturers since there is no common participation in uniform testing to measure rack performance. 
• Nos. 6 through 11 are opinions.
• No. 12 is a nice-to-have opportunity, although less common due to the size/weight of equipment racks and the custom-built nature of some of them.
• No. 13 is a lofty goal for a rack (my opinion)
• No. 14, well...

In the end, people buy what they buy and I suspect the reasons are a combination of appearance, perceived performance based on information the buyer has reviewed and on recommendations by others, persuasive marketing, and price.  Most who "upgrade" (to a usually more expensive option) generally say the upgrade is "worth it."  However, this may have as much to do with confirmation bias as with performance.