It just makes sense. Everyone is different, tasks are different, projects are different. It's all different. Pretending that everything is the same, is predictable, and can all be controlled -- not only doesn't it work, it complicates things terribly because you're constantly struggling against an impossible goal.
The troubles begin with the definition of "results." If the desired result is to create a new product, that's a good goal. But if you're determined to overconstrain the problem, it won't solve anything to declare that you have a ROWE. If you say that the "result" is to create the desired thing within this period of time with a fixed amount of cost (that is, you try to break out of the iron triangle), you can produce a situation where everyone is still working far too hard.
I suppose this is a power-hierarchy problem. As long as there's someone else deciding what the desired results should be, that person in power might have incentives to, effectively, destroy the intent of a ROWE.
There is a class of business where it's very difficult to separate hours from productivity. In service industries like retail, restaurants, and the like, "working" primarily means being there at the expected times, and physically doing things. Most business schools ultimately base their theories on Frederick Winslow Taylor's (fraudulent) "research" showing how long it took to load iron ingots onto a railroad car, purely physical labor where the worker is simply a machine that can work at a certain rate.
In service industries, it's hard not to make a one-to-one association between hours and work. But when a restaurant closes for the evening, things shift to ROWE during cleanup and prep for the next day: it doesn't matter how long it takes as long as it gets done. This gets a little confusing: "am I being paid for my time, or for my productivity?" It's different at different times.
Manufacturing used to be the same, before mechanization. But now, the task is a creative one: how can we mechanize this work? In manufacturing, we've gone from the most hourly of jobs to the most ROWE of work. (Aside: every time the news tells you how "manufacturing is going away," what they don't say is that it's manufacturing JOBS that have steadily gone away. And they mostly haven't gone overseas -- they've been mechanized. This produces cheaper, better goods but it means those jobs aren't coming back. Ast technology improves, mechanization accelerates. And the bottom line is that the U.S. is still the #1 manufacturer in the world. It's just that machines are doing the manufacturing).
We have been acculturated to "working hours," and that's the biggest hurdle. You can declare all you want that you have created a ROWE, but if everyone still feels like they are being judged on the hours they put in, I'm certainly going to feel it. I'm not going to be able to say to myself, "During the past two hours, I created as much as I'm going to do all day. If I keep working, I'll just be spinning my wheels so I should stop and do something else." Heck, I can't even do that now and I work for myself! It's usually something like "writing that code was such a rush and it felt like I accomplished so much. If I keep pushing, maybe I can get that feeling again!" But over and over, I discover that the extra time is mostly a waste, and that I'd be far better off doing something else (but I often don't have anything else to do that's equally compelling, so it's partly a task-management problem and partly the ability to switch my attention and enthusiasm).
I certainly don't want to say that ROWE can't work. I've worked too long within my own semi-ROWE world to even consider going back to the hourly grind. What I am saying is that you can't just throw a switch and say "now we are a ROWE." The most enthusiastic supporter of ROWE has already been thoroughly trained by our culture to watch the clock. For it to work, the fundamental structure of the organization must be built around the ideas of ROWE. I suspect that in the vast majority of cases, ROWE cannot be implemented as an afterthought.