I'm an agent in Virginia (and a real estate investor), and my wife is a home stager. So here's a double perspective, at least from the East Coast.
A couple of years ago, agents didn't see the need for stagers because the houses would sell without staging. Sure, the argument was that they'd sell for more, or (except during the peak, when anything would sell instantly) that they'd sell more quickly. But someone who'd bought at, say, $250,000 didn't much care whether that home'd sell for $600,000 or $625,000, or that it'd sell in 15 days rather than 30 days. So, some agents who began their careers then don't have the perspective to understand the benefits of staging.
But today is different. And the agent's mantra is "Price is everything" and "If it's not selling, lower the price." Well, sure, nearly anything will sell at some price. But not all agents (and homeowners) understand that it may be far more economical to stage a home for, say $5,000 than to cut the price by $15,000. That's especially true if the house doesn't show particularly well. It doesn't have to be a dump...and that's what agents don't understand.
In addition, not all agents are willing to be honest with their clients about their homes. You have someone who has lived in a home for 25 years and it's their pride and joy. There are the pictures of their three children on the walls...many of the walls. Plus hubby's diplomas and certificates of achievement. There's the artwork they bought in Peru, and the Chinese wall hangings they acquired over there. They're religious, so there are plenty of framed prayers and pictures on the wall. The last of their kids is at college now, but the kids' rooms were the way they left them--little Sally liked pink, so everything in the one bedroom is pink. Billy was a bit of a rebel and liked black. He wasn't really a goth, but that's the style of his room. The whole house is full of memories. It takes a good agent to talk reality to the owners. Many of them don't have the courage to do so.
I don't disagree with Phil that many clients don't want to pay for the service. Partially, it's because they don't understand the benefits, and their agents haven't informed them of the benefits. ("Well...we could stage it. It'll cost you some money up front and there's no guarantee it'll sell your house. You can do it if you want, but most of my other clients haven't. And, really, price is what's going to sell your house. Now, let's talk about a price readjustment. I can get that into the MLS this evening."
The agents out here who've tried it seem to see the value in it. And I've seen some agents who've taken the courses themselves and actually do a pretty good job themselves. It's not "real" staging, but it does declutter, organize, and better present the house. And I know some investors (rehabbers) who really see the value in staging. They're willing to spend some money to sell a house quickly for top dollar.
Anyhow, that's my observation.