I have many times considered getting my PhD in Rhet/Comp over the last few years, and have been through the same thought processes you mention. I looked into the Texas Tech program, but while it allows some flexibility to plan your own focus, I don’t think it would necessarily be a good use of money at this stage of my career and life since I would have to pay out-of-state tuition. I believe there’s also an online program at Old Dominion in English, but again, it’s a cost issue for me.
Recently, I visited University of Nevada, Reno, to check out their program in English Literature and Environment, which is more what I’d like to focus in, since my undergraduate degree was in Geography. I am trying to determine now if I want to commit to an additional five years of school; I love school, but have other obligations – including working full-time – that make it a harder decision for me. Would the payoff be worth it? Hard to say. I think I’d have to go into it because I’m truly fascinated by the subject matter, rather than thinking I’d necessarily get a huge return on my investment.
I teach many, many developmental writing and composition classes. I see every day exactly what you are referring to. I think teaching writing (especially early writing classes) is often difficult to do online, mostly because students benefit from hearing immediate responses to their questions and immediate corrections to their misconceptions. While I applaud students who return to school to obtain degrees, too few understand what “college writing” really means. They need to see that writing is learned by many years of practice, and not a 5-week or 9-week class or even 16-week class.
I don’t mean to be negative, and I do my best to help as many as I can. But the challenges are definitely there, both online and in the traditional classroom.