I would say it's the equivalent of going through the process of jumping through hoops to be a contractor at a company, maybe doing some jobs (or not), and then failing to respond at all if they send some work your way. If you show yourself not responsive to their time constraints, they very well may decide it's not worth notifying you of work items, and ignoring any bids you submit.

Contract work is all about trust. If you show any behavior that makes you look less reliable, are they going to trust you with work? Flipped around, if the company doesn't respond to requests for payment, are you going to want to do work for them? It works both ways.

Why not?

It's equivalent to submitting a lower bid.

(The point is moot though because apparently Uber rolled out a feature that allows drivers in California to set their rates).

A town wants a bridge built. They set a maximum price. Three contractors submits bids. They are all at the maximum price – instead the contractors differentiate themselves based on quality of previous work and distance to the construction site.

A fourth contractor thinks the price is too little and rejects it outright.

The fourth contractor has "submitted a lower bid"?

The fourth contractor submits a bid above the minimum price.

Yes, sorry, I misspoke (edit: actually, I think you misspoke in your previous comment, and then I copied the mistake).

But no, the fourth contractor did not submit a bid at a higher price. They did not submit a bid at all.

Ah yes, indeed I did.

I see your point too. Essentially, rather than contractors proposing prices and then clients accepting or moving on, if clients propose prices and then contractors accept or move on, it's still a market with negotiated rates.