While ESL students are "just like" other students as far as global needs are concerned, they are also a group with specific needs. They need lots of individual attention because many of their writing problems are unique. And they benefit from having a section of composition to themselves because they are often very lonely, far from home and family, and they are comforted being part of a group of others with similar circumstances. It's easier to write when you are working with other writers who can identify with your particular set of difficulties. It's easier to participate in class when you don't have the added burden of worrying that no one will understand what you're saying because of an accent, and worse, no one will care to have you clarify because it's too much of a bother or too awkward.
Foreign students at CSU are fortunate to have a CO150 class devoted to their needs. And it is important to recognize the needs of the ESL student in the writing classroom. We have found that English is best learned through writing and speaking. Grammatical and mechanical errors tend to be easily taken care of when students are learning important communicative skills like focus and purpose, so it is important to structure a classroom in ways that benefit ESL students most.