Are backlink generators helpful and should we use them?
If not, why?
No because they get you links with little to no value (usually no value). What good are having backlinks if they don't bring traffic or have a positive effect on your rankings? Not to mention, it's very possible these generators will place a large quantity of links in a bad neighborhood. If you reciprocate any of those links you will most likely be associated with that bad neighborhood and incur any penalties set upon sites in that neighborhood.
Just get backlinks to the natural way. Write good content and get others to want to link to you. One quality link from a related site will be worth more then hundreds of the crappy links those generators make.
To answer your question, "are they helpful?"
Usually, yes. At least they can't hurt. No one can hurt your site off-page. This is often mis-stated. (I'd venture a guess that I'll get challenged on it here.) I've read community discussions where black hatters dared others to get them penalized off-page, stating the obvious: if you could get penalized for backlinks, wouldn't competitors point backlinks to the sites they want to beat out?
To answer the "should you" part of the question:
I think it's valid to look at your competition in order to decide. If they are not buying links and deploying mininets or linkwheels, then please don't be the first in your industry to set that in motion, and consider yourself lucky that you don't have to compete with cheaters.
Lastly, here is a useful suggestion you can use to build up your backlinks. I have often looked at competing sites and noted where their backlinks came from. Often times, they are listed in directory sites and local business sites where you can create a profile page. I made certain that the no competitor was listed on an open site that I did not have a listing (and backlink) from.