Recently, in response to President Obama’s proposal to make community college free nationwide, I wrote a piece for the Washington Post that ran under a headline calling community colleges “terrible.” It elicited numerous angry retorts, several of which suggested people read actor Tom Hanks’ personal reflection on his community college experience instead. To this I offer two major thoughts: (1) Op-ed writers often don’t write their own headlines, and (2) thank you, Mr. Hanks, for illustrating a major concern.

First, I don’t think all community colleges are “terrible.” That’s why you don’t see such terminology in the article itself. I do think the sector performs “poorly,” and we would be ill advised to spend billions of additional federal and state dollars on it, but that’s not the same as calling all community colleges terrible.

The main indicator I used as evidence that the sector performs poorly is its very low completion rate. I used the 150-percent-of-expected-time rate for first-time, full-time students, combined with transfer rates. I used data from the federal Digest of Education Statistics and a National Student Clearinghouse Research Center report, and estimated a “success” rate of around 34 percent, including people still enrolled. A six-year rate reported by the Clearinghouse that I did not cite gives slightly better, but still sobering, news: Only 39.1 percent of community college students complete at either their starting or a different institution within six years, while an additional 17.9 percent remain enrolled.

“Ah, but,” responded many community college defenders, “lots of people don’t finish because they have gotten what they need without completing a degree or certificate.” When asked for evidence, they have typically said that tracking such things is hard — many people leave without reporting why — and good data are difficult to come by.

That may well be true, but when the President proposes spending $60 billion in federal money, and another $20 billion in state funds, I’d like more than just “don’t worry, we know it works out well.” And it’s hard to ignore reports that eight in ten community college students have a goal of attaining a bachelor’s degree, but only one in ten actually does so, at least in six years.

Of course there are many reasons people don’t hit their goals, but it’s easy to believe that a major one is that community colleges, which are quite cheap to students, tend to attract people who are either unprepared for college-level work or who feel little urgency to complete such work. We can look at the massive remediation rates at community colleges to see this, but it is also where Mr. Hanks comes in.

While Mr. Hanks writes that he couldn’t afford a four-year college, he was also “an underachieving student with lousy SAT scores.” Translation: He didn’t try all that hard. And what did Mr. Hanks do while in college? It sounds like he mainly enjoyed himself, hanging out and giving class presentations that sometimes “did nothing more than embellish the definition I had looked up in the dictionary.” What Mr. Hanks illustrates is that just as it is possible that many people do not officially complete because a few classes give them all they need, it is also possible that many students leisurely linger, as Mr. Hanks seemed to do.

It would, of course, be fine if Mr. Hanks and others smelled the roses on their own dime, but they don’t. They do it primarily on taxpayer dimes. Community colleges aren’t alone in being subsidized places of leisure, nor do they offer the biggest indulgences, but it is nonetheless easier to relax when someone else is paying your bills. And today, when you throw federal grants to students in the mix, taxpayers annually supply around $9,700 per community college student. That’s money coming from real, flesh-and-blood people who might have invested it, or used it to put food on the table, or for countless other things.

Finally, while Mr. Hanks wrote that he didn’t have the money to go to another school, community colleges are not purely lifelines to the poor. Indeed, according to recent federal data, 38.8 percent of dependent students at public, two-year colleges come from the upper half of the income distribution, as do 54.3 percent of independent students. 15.5 percent and 28.2 percent, respectively, come from the highest income quartile. So the relatively well-to-do may often be the ones enjoying taxpayer-funded leisure.

“Free” education sounds terrific. But there are always prices to be paid.