Of course, it's a ploy to encourage more manufacturers into F1, but until all the teams build their own engines like Ferrari, or Cosworth can supply everyone, this is a necessary evil.
It may have several benefits for the racing, though. The current frozen engine specs mean development is locked down, and differences between engines are minimised. The new framework will inevitably leave more room for innovation and difference.
Turbo engines should introduce another variable and teams/drivers can offset the level of boost against fuel consumption, so as in the 1980s there should be a mix of conservative/aggressive strategies through the race. This happens already to an extent, but with a turbo the effect should be more pronounced (bigger difference between the different "modes")
An environmental policy may pave the way for a fuel, or energy, limit, which could be a way of controlling the pace of the cars from year to year without constant tinkering with car or tyre dimensions. This might allow more freedom in car design.