the smug attitude demonstrated in this article is not helpful, especially considering that the point that they're making is actually wrong.
it is true that mutations happen all of the time, and they're not always successful. a mutation is indeed just an error in transcription. sometimes, a mutation may have a positive effect on the organism's ability to survive and reproduce (in which case we'd say the organism is evolving), and sometimes the mutation may have a negative effect, and actually harm the organism's ability to survive and reproduce. most of the time, a mutation won't make much of a difference at all.
the reason that the issue of mutation is concerning in the united states is that the health care system is inaccessible to such a large percentage of the population, which means you're going to have thousands of people catching and spreading this disease (and probably already do.) outside of the understanding of health care professionals.
the trump administration seems to think you deal with this by quarantining people. if you just stop people with the disease from moving around, you should easily stop it, right? so that's why there's only a few deaths - the quarantine is working! but this is a retarded argument that health care professionals in every other country in the world will instantly reject as anti-science. quarantining people isn't actually likely to actually work and, worse, it generates large amounts of fear. i'd have a greater fear of getting quarantined than i would of dying of this, so if i thought i was going to end up quarantined, i'd avoid going to the doctor. so, what health care professionals everywhere else in the world will tell you is that you want to strenuously avoid policies that promote quarantine (except as an absolute last resort, with an extremely potent virus - which is not this.) because it just acts as a disincentive to get tested, which just spreads the virus even more. the argument you're hearing from the administration on this is completely backwards; the policy of quarantining is just another reason to think that the number of cases is likely dramatically under-reported, and is even probably one of the causes of that under-reporting.
so, how do you deal with this? what you want to do is make it as easy as possible to get tested, and ensure that the disruption to people's lives is as little as possible. you want incentives to come to the hospital to get treated, not incentives to stay at home or go to work and let the thing run out of control.
how often do flu viruses mutate into different strains? well, why do you think you need a new shot every year? and, why do you keep getting it, even after your immune system has defeated it? so, the answer is fairly often - often enough that you have to keep taking flu shots.
we don't have data on how fast this thing is going to mutate, and that's really the mistake the article is making. if the inaccessibility of the american health care system means it ends up circulating in the population like the flu and ends up mutating at about the same rate as the flu (a rough guess, based on nothing.), then we could very well see the country act as an incubation area, and be in a situation where the rest of the world is playing catch up to these different strains that keep mutating in the american workforce, because it can't get access to basic care.
and, that is a real concern to look at it - regardless of how this smug article from the msm frames the issue.