In Chicago we have been offering an hourly rate a little above $100/ hour for several years. We are probably the only brokerage doing that.
There is an entire field of economics devoted to irrational decision making. It's called behavioral economics. In this case the consumer over estimates the risk of an hourly model costing more than a traditional commission model. Therefore, I find that only really analytically smart people are doing this when they are fairly certain that they won't need much of our time. The rest think it's too risky.
When it comes to hiring real estate agents I've observed all kinds of irrational behavior.
On the agent side...well, the average real estate agent is not the sharpest knife in the drawer. They cannot wrap their head around the notion of the value of their time. Also, they prefer an uncertain big payoff to a certain but lower payoff - even when they on average earn more per hour if they just charge for their time. Makes no sense. It's the same reason people gamble.