But the ETH route seems the only viable solution for most, since almost everyone has a GPU in their computer or can acquire one.
I would have agreed a month ago. But I think Bitmain's S9 is a game changer for many. Getting like 2/3rds better efficiency means many that mine with a S7 now will be able to mine after having using a S9 which is a nice surprise.
So there is a chance for those with more "normal" electricity to still be able to mine after having with S9. S7 still will remain a good machine but it's harder to speculate what the highest electricity price that makes sense to keep mining it will be. So some with "cheap" and "free" electricity might get some S7 deals after having. All speculation really at this point.