Food, oxygen and water are useful to the Klingons, but Starfleet does not glass entire planets just to keep the enemy from using them.
Apparently, you're completely oblivious to the
Geneva Conventions:
Articles 51 and 54 outlaw indiscriminate attacks on civilian populations, and destruction of food, water, and other materials needed for survival. Indiscriminate attacks include directly attacking civilian (non-military) targets, but also using technology such as biological weapons, nuclear weapons and land mines, whose scope of destruction cannot be limited. A total war that does not distinguish between civilian and military targets is considered a war crime.
[. . .]
Article 35 bans weapons that "cause superfluous injury or unnecessary suffering," as well as means of warfare that "cause widespread, long-term, and severe damage to the natural environment."
Scorched earth:
It is prohibited to attack, destroy, remove, or render useless objects indispensable to the survival of the civilian population, such as foodstuffs, agricultural areas for the production of foodstuffs, crops, livestock, drinking water installations and supplies, and irrigation works, for the specific purpose of denying them for their sustenance value to the civilian population or to the adverse Party, whatever the motive, whether in order to starve out civilians, to cause them to move away, or for any other motive.
Geneva Protocol of 2155:
The Geneva Protocol of 2155 was a treaty created in 2155 in Geneva on Earth, prohibiting the use of biological weapons. In 1928, a previous treaty dealing with this subject had been created.
Michael Burnham cited both Geneva Protocols in a discussion with Gabriel Lorca in 2256. (DIS: "Context Is for Kings")
The Geneva and Hague Conventions, which, evidently, exist in the
Star Trek universe, usually go together. Unless, for some reason they've abandoned the former and kept the latter.
Also, I don't know about Starfleet's aforementioned "high-minded principles," considering Starfleet Command's decision to approve the forgery of evidence in order to bring Romulans into war in
DS9: "In The Pale Moonlight":
SISKO: . . . Starfleet Command had given the plan their blessing. . . .
Plus, there is the
Voyager with its banned (by the Khitomer Accord) subspace weapons.
Speaking of the Geneva Conventions and Protocols or the Hague Conventions, are there any that would explain the situation with the
Shenzhou and the
Sarcophagus?
In the meantime, have a look at this
Trekyards episode analysis linked to the relevant part at
15m16s, as well as their additional analysis titled "
Why was the Sarcophagus ship ignored for 6 months?" for a similar discussion, if you like.
That's all.
