'certain' in this context means: those H1B holders who have completed 6 years of the original visa term. They are compelled to either wait and languish in line, or go back home where their spouse can work.
Where do you see that? If that is the case then it helps only those who applied for permanent residency late in their 6 year H1-B term hence they don't have EAD for their spouse through green card application but can extend their H1-B status indefinitely.
Edit: Not sure why I got downvoted. I was just paraphrasing the reasons given in the proposal. Its not an opinion. Don't shoot the messenger. See http://www.reginfo.gov/public/do/eAgendaViewRule?pubId=20131...