You're certainly correct, but brevity of the writer and intelligence of the reader means I don't have to be explicit about every point, just as if I were to write that a cockpit altitude alarm is telling a pilot he must act with increasing urgency to pull a plane up from a perilous dive.
I could be explicit, and say that the alarm itself is just a combination of electrical circuitry and detectors that change behaviour due to input thresholds, and that the alarm does not particularly care whether the plane crashes or not, but I trust that the reader understands what I'm saying when I say the alarm is telling the pilot he must pull up.
In the case of a cockpit altitude alarm, "pull up from a perilous dive" may not be the appropriate response; "lower your nose and throttle up to build airspeed and get out of a perilous stall" may instead be called for. Additionally, pilots will universally agree that it is worth taking certain actions in order to avoid crashing. Thus, the use of shorthand in that situation is fairly reasonable.
When it comes to declaring what science tells us we "must" do, the picture is far less clear. One reason to be explicit about the difference between "is" and "must" is that even intelligent readers and writers sometimes hold mistaken beliefs here. Another reason is that, even among those in total agreement about the science and in total agreement about certain predictions, there is still disagreement about whether various tradeoffs are "worth" the cost. At that point, science is simply the wrong tool to tell us what we "must" do.
You're certainly correct, but brevity of the writer and intelligence of the reader means I don't have to be explicit about every point, just as if I were to write that a cockpit altitude alarm is telling a pilot he must act with increasing urgency to pull a plane up from a perilous dive.
I could be explicit, and say that the alarm itself is just a combination of electrical circuitry and detectors that change behaviour due to input thresholds, and that the alarm does not particularly care whether the plane crashes or not, but I trust that the reader understands what I'm saying when I say the alarm is telling the pilot he must pull up.