Student loan creditors such as Nelnet are required by law to report accurate information to credit agencies. This makes dealing with late or defaulted student loans much different than other accounts. Basically, regardless of if you have consolidated, or even undergone a rehab program, the record will remain on your credit report for 7 years.
You can read why student loans cannot be included in a bankruptcy on the ed.gov website for the specific legal mumbo jumbo.
Most other accounts CAN be negotiated
…if you go about it the correct way. I wrote about the best way to negotiate charge offs, late payments, and collections in this article about removing negative credit report entries.