It's worth looking at the context of the quotes, to understand why they say that, and what they recommend instead.
The first citation is from an article which recommends acupuncture (and more generally "Doctors of Oriental Medicine and Acupuncture Physicians"). There seems to be some legitimate doubt about Acupuncture ... therefore (because it doesn't suggest an effective alternative) I would discount its (somewhat vague) criticism of western medicine (I would argue that anyone can be a critic, but the criticism is meaningless or not constructive unless there's a better alternative).
The second citation has exactly one concrete example of its thesis: which is, treating atherosclerosis using "heroic/interventionist" pharmaceuticals, instead of by "addressing the source of the problem: the patient's lifestyle". I'm not sure what source you consider a credible reference on the subject of Western medicine; there are many of them. I will choose the Mayo Clinic as an exemplar: the opening sentences/paragraph in the "Treatment and drugs" section of its atherosclerosis article says,
Lifestyle changes, such as eating a healthy diet and exercising, are often the best treatment for atherosclerosis. But sometimes, medication or surgical procedures may be recommended as well.
Its next section recommends Lifestyle and home remedies.
The claim is somewhat true, if [only if] you define "Western medicine" as "prescribing medications". In practice, Western doctors (perhaps especially "Family doctors" aka "General Practitioners") routinely do more than prescribe medications: for example they also talk with patients, ask them questions, and give lifestyle advice.
In summary, Western doctors /also/ prescribe medications: they don't /only/ prescribe medications.
The term "medicine", used in the OP, has two meanings:
1. The science or practice of the diagnosis, treatment, and prevention
of disease (in technical use often taken to exclude surgery).
2. A drug or other preparation used for the treatment or prevention of
The claim is:
- Untrue per the first meaning of the term (and IMO the first meaning is implied when it is spelled with a capital-M: "Western Medicine").
- Truer per the second meaning of the term.
Wikipedia's General Practitioner article starts with:
A general practitioner (GP) is a medical practitioner who treats acute and chronic illnesses and provides preventive care and health education to patients. "The good GP will treat patients both as people and as a population".
As a difference to medical or surgical specialized doctors they intend to practice a holistic approach that takes into consideration the biological, psychological and social environment in which patients live. Their duties are not confined to specific organs of the body, and they have particular skills in treating people with multiple health issues. They are trained to treat patients of any age and sex to levels of complexity that are defined by each country.
IMO this shows that the theory is false, at least according to the opinion of "Western Medicine" itself!
There is of course some difference between theory and practice. For example, the British What is a good GP? (from 1987) opens with,
Treating patients as people
It has been said that "though sometimes 'what is the illness' is the
question dominating the doctor's task, 'who is ill' is what is usually
crucial to patient care."' What this implies for good practice falls
under the following four headings.
Assessing patients' problems realistically
Making a precise diagnosis is not always necessary or always sufficient. It is all too easy to
focus on a disease process in one part of the body and to neglect the
"owner" of the body and his or her physical, psychological, and
social circumstances in their entirety. Unless these aspects are
considered, not only may many factors that affect the aetiology and
natural history of the disease and the choice and effectiveness of
treatment go unnoticed, but so may the patient's real reasons for
consulting the GP.
IMO this shows that Western Medicine isn't supposed to only treat symptoms, and that if (but only if) best practices like these are followed then it won't.
However it is (sometimes, or, often) less true in practice, for example because of time+money constraints (see for example rob's answer).
I expect that it is also less true of various Western medical specialists, for example, a surgeon, to whom a GP will refer you iff s/he thinks that's appropriate for you.