The problem here is that those frameworks/plugins/existing API's are all moving targets, their life-span is very likely substantially shorter than the life-span of your project.
Well vetted and popular unfortunately does not equal 'will have staying power'.
No, I think it should be fairly obvious that that would not be my choice, rather the opposite.
But why django? Why not rails? Or symphony? Or Yii? Or Spring? and so on, why git? and not subversion, or tfs or mercurial? and so on. For every one of those choices there are 10's of possible choices and none of those will be something akin to an industry standard. And so we muddle on. Well, at least git seems to become slowly the standard in revision control, but because git was yet another fresh start project a lot of the lessons learned from other revision control systems that were not readily apparent to the git author(s) had to be re-learned the hard way, resulting in a lot of delay and frustration (and to this date the git command set strikes me as ill thought out).
Leveraging open source in a smart way is exactly the right thing to do, now if only there would be some kind of mental penalty to start a new project when an alternative is already available which could use some TLC.