I'd argue it's the same thing. At the end of the day, keeping focus or not is a cost-benefit analysis.

Put another way, focus isn't something to value in absolute, it needs to make sense in business and opportunity perspectives. You say No to good ideas only if you're confident your current plan is good enough and worth pursuing on its own.

Right, I think that your interpretation here is basically correct. There's a lot of different words and ideas we can use to represent approaches to problem solving, and they're going to overlap a lot. And I think the exercise of treating them like they're mutually exclusive and "correcting" our choice of language by saying one term is more correct than another, more often than not, is just kind of tedious and beside the point. It's a good general rule of thumb for understanding any of these articles, and affording them what the philosopher Daniel Dennett referred to as the principle of charity.

It's not to say that such corrections are never appropriate but that the principle of charity step should be completed before going into the exercise of attempting to correct language.

Exactly. The author is arguing that certain ideas looked good but at further inspection were actually less good.

Rejecting a genuinely good idea is much harder.

Rejecting these kinds of ideas - business adjacencies - is especially difficult. I've worked at a number of places and every single one did this exact thing - lost focus on sensible sounding adjacencies.

Even Google does this of course :-). They can afford it.

They are the worst offenders. Maybe they can afford it, but I'd argue it costs more than they'd like to admit.

He isn't explaining cost benefit, he's using cost benefit. And basically saying people don't do a good job thinking through the cost side and/or it's harder than it seems.

I agree the first two points are more about understanding trade-offs - but the result is still focus. Overall I thinks it’s a good articles about achieving goals. Focus can be an overused word, but still works well here IMO