E-cigs won't ruin vaporizers. I'd see it more likely that e-cigs get ruined by vaporists' reputations. I think vaping could get caught in a perfect storm between e-cigs and dabbing.
I am not so sure, my thought is dabbing is a bit too strong for some folks. I've been at this 20+ years, and not so long found dabbing. What I find is while I do kind of love it, it's just too strong for me to want to do all the time. Although a dab of a nice sativa does give me a good kick in the pants.
I am in the camp that agree, vaping will be the slower replacement to smoking/puffing. It has more of a habit, leveled control, and things like pax and ejuice make it so convenient and easy. It took me a long time/effort to get to an E-Cig that feels satisfying, I am on day 7 of no cigarettes now.
Same for the vaping.... the PAX and FireFly were really the first vapes that I found myself reaching for before rolling a spliff. The buddah, or bigger things i tried in the past, just had no experience to them, it removed all the fun/process out for me.... i think process is part of what people end up growing into enjoying in their habits. Like the meditative aspect of breaking the nug, prepping, rolling... etc.
Interestingly, I will admit, that by far the best e-cig I have or tried was the JoyTech eroll, it can do anything and never breaks. It's main issue is battery life and tank size and price. If more devices came out that had their reliability, comfort, and experience... at a lower price point, i think they might have already won this game against cigs. In the meantime I am happy to have found my cloupor and aspires as well.
So in short... I think vaping and e-cigs will find a happy merger/medium in their devices.
I think dabbing will not go away, but it won't replace anything... except maybe harder things.
I think dabbing will be more popular in the portable pen world as those improve, and the dab-rig will be like bongs... more for the heavy stoner/college/party hardy crowd... and the aficionado to enjoy a treat now and again.