I am a cheerleader for MORE student voices in the high school press, and informal essays (we like to call them commentaries and/or columns) are a prime method of "hearing" those voices.
Perhaps our toughest job is to encourage our writers to move to "higher" levels of criticism, rather than focusing on pet peeves and on low level concerns (building temperatures being all over the place, the relative crispness of the tater tots at lunch, etc.).
Higher level concerns, such as the quality of education students are getting in a school, or the rising inequalities in American life (and maybe in our own schools), now THOSE are "grumblings" I am eager to read.
Insisting on two pages each issue, when sometimes you have three pages of good thinking and other times you really only have one page... well, that's just slavish devotion to a non-existent rule.
Deirdre's point about encouraging real reporting to accompany opinion is a good one. By way of example, I just finished reading this morning's New York Times front page in-depth on homeless children in New York. It's part one of a series, and it illustrates perfectly a version of Ernie Pyle's advice: If you want to tell the story of a war, tell the story of one soldier.
Our version: If you want to tell the story of a school, tell the story of one student.
Sometimes you need to tell it in third person, with at least a thin veneer of objectivity, as in http://www.nytimes.com/
[The reporting is so compelling that no reader can come away from this piece unaffected. I read elsewhere this morning that 20 percent of American children are living below the poverty line, placing the U.S. just above Romania among developed nations. There are no countries below Romania in this ranking.]
Other times our students just need to bust out first person and share on the page.
You (and the complaining faculty friend) and your students don't have a problem. You have an opportunity.
Kids who don't care, don't grumble. Your kids care. The question for you and your students is more about how to get OTHERS to care.
All the best!