"Telecommuting was a nice experiment, but it doesn't work for people whose work is not easily quantified."
And who are those people? I've always quantified my home working staff's work based on results. Have they got done what I've expected them to do in the time I expect them to be able to do it? It's not really rocket science.
"In theory, it may be possible to identify the people that are more productive, but that takes a lot of management effort"
Yes, it's so effortful to determine who is and isn't pulling their weight. Honestly, please don't become a manager. Ever. If you can't even begin to understand how you might gauge which of your staff are effective and not calling such understanding merely "theory" then you're really not cut out for such a role. If you've any experience managing people then it's fairly easy to see who does and doesn't get done what they need to do. Dealing with the problem is often the hard part, because you can often be hamstrung by company or national policies on the issue depending on who you work for and where you live.
"since, obviously, the people that do NO work at home are the people that like telecommuting the most."
Yes obviously. Thank you for the wealth of proof you provided for your assertion.
"Although it wasn't popular, Marissa was right to end the practice at Yahoo."
Yes, if by right you mean she found it easier to lose talent than actually do a job of managing any real or perceived problem. The problem is there are as equally unproductive amounts of people as your pulled out of thin air numbers in the office too. Unproductive people are unproductive, it doesn't matter where you make them turn up for work. It doesn't fix the root problem- they're unproductive because they're not motivated, and they're not motivated for any number of reasons- unhappy with compensation package, being managed by a hopeless manager that demotivates people, being repeatedly given the most boring work, being forced to do things not in their contract that they don't want to do, not being given a fair shot at career progression or training and so on and so forth. If you don't fix the root issues your people will still be entirely demotivated and unproductive. Some of these things are your fault as a leader and you can fix, others you can do little about- someone has to do the boring work and the best you can do is help them move on.
Meyer's actual claimed reason for getting rid of it was because she wanted people in the office bouncing ideas off of people to try and spur on innovation. I agree with this to a degree, I think during product conception phase this is absolutely right, but the problem is this whole bouncing ideas off each other open plan office mindset falls apart when it's time to stop coming up with ideas and start implementing them. Once those ideas have formed a product, and you've got down on paper what your bounds for this product are, and you need to start planning and building it, people need a few days a week to actually get on and do that in the environment they're most comfortable in where they're not going to be repeatedly distracted. For some people this is the office, some this is the local cafe, some it's in the park, and for others it's at home.
And that's why Meyer's blanket ban was bad. There's no question she'll have lost some talent doing it as she did. But when you claim your goal is to stem the flow of talent out of the company, then such blanket actions are doomed to fail. It's short sighted lazy management that makes great headlines, whilst shedding you real actual talent, and doing nothing to stem any apparent company wide problem of poor motivation. Even if she has got more people into the office coming up with more ideas, she's not enabling an environment that ever lets all her people put those ideas into practice- the only ones that will be productive are those who can be productive in an office environment, which isn't even close to the whole of the human race, maybe like you I'll make up a percentage, I'll say it's about 40% of staff leaving 60% unproductive. Yeah. That sounds about right looking at your typical office that doesn't allow home working and has hoardes of staff organising pointless meetings to break up the monotony of office interruptions, or hanging around the water cooler just to try and make time pass more quickly.
You don't fix productivity and motivation problems by pissing people off even more. This is such a simple rule, but I'm constantly astounded by how many managers and wannabe managers alike fail to grasp it.