Life outside Earth - we could have a problem

I can't remember if I read about this idea somewhere or it's just something that my brain compiled from other information, but I was thinking about life on other planets when I realised that there might be a problem.

There was a TV program a couple of years ago which said that Jupiter acted like a giant spounge which essentially protected the inner planets from direct hits by attracting and swallowing space debris using it's massive gravity. This has probably protected us from pottentially millions of small impacts and quite possibly a lot of large ones.

Now if this was what allowed life on Earth to exist and grow through the rather violant stages of the relatively early Solar System - would this also be a key if creating life on another planet in another solar system?

In otherwords, would the existance of life not only require the right conditions and elements like amino-acids, but also a big gas giant which would rather narrow down the chances of life, never mind intellegent life considerably?

I'm not saying that it doesn't exist especially when you consider the size of the Universe and since the outer parts are much more settled, this would pose less of a problem, but could still pose the occasional hickup.

Back to mad theories....