I can't believe I'm saying this at 28, but that's a really young-person point of view.I'm 48 and disagree with you completely. Email is long-form written communication - which we've been doing for hundreds of years (letters, essays, books, and much more recently, email). We (my generation, the ones before, and the one or two immediately after) grew up with long-form written communication.
I've long been of the opinion that telephone conversations have no place for serious ideas, because they are conversational, because they are mostly made up on the spot. Serious ideas (business proposals, scientific research, system and software design, novels) require long-form written communication because it forces you to think, to organize, and to express clearly.
Email - and Usenet and modern fora such as this one - can be used effectively for this same long-form written communication.
The generations I am concerned about are those that grew up with PowerPoint and SMS and Twitter: These media favour catchphrases, sound bites, etc.
Yes, there have always been these - but once upon a time they were a specialization that required thought. Witness copywriting and Churchill's famous comment about prepping a two minute speech. More recently, these became the de facto standard, legitimizing the sound bite conversations of a great many second rate thinkers and managers.
The long-form business plan, long-form business communication of any kind, has slowly dwindled, replaced with bullet speak and now tweet.
I would argue that the opinion expressed in the original article is in fact the oldest of old-school ideas: If you cannot take the time to think through what you are trying to say and compose a meaningful email, then I will use that as a first-pass filter and remove you from my overloaded queue.
If you cannot take the time, you are not worth my time. Most of the time.
Yes, email can and often is used for bullets and tweets. Sometimes that's appropriate. That's one of the things I like about email: It is largely content and length agnostic.
I am very much relieved to know that the preference for long-form remains alive and well, even if somewhat hidden. Bullets and tweets and soundbites will grab attention, which can be fine, but will generally fade. Except for those very few well-crafted sentences of lasting impact.
I would guess that the proportion of lasting impact to total expression in long-form is much greater than short-form for two simple reasons: There is far less of the former and its overall quality is simply higher on average, and there is much of the latter with so much noise and so little signal.