No... VC firms don't have any stake in creating low vs. high paying jobs. They have a stake in making a company successful. They profit the most when the company succeeds. You will have some that try and do what the Obama admin claims Bain does. But those firms don't last long. They get a rep for doing so and no one will fund them anymore.
Most of the high paying jobs in Silicon valley are a result of Venture Capital firms. We have several VC funds here in CO designed solely to fund ideas/products in the clean tech arena. Others that are involved in biotech. That is how these high risk/high reward start ups are funded. It is not done with bank money (they are restricted from such).
When a company is struggling to survive, no matter how long they have been in existence, VC firms will come in and if they think they can be turned around, will try to do so. They are not always successful. If the success rate was north of 75%, then funding wouldn't be so hard to find for those firms. Sometimes the market just works against you... as is the case with GST. Obama won't tell you that over a dozen of the top US steel companies went under at the same time... not because of bad management, but because of cheap steel coming from Asia etc...
VC firms are essential to the economy. They are essential to R&D.
I say this as a private equity investor. The biotech firm I invested in could return me 5-10 fold on my investment. Or it could go to zero. That is the risk/reward of many private equity/VC deals.