@Setanta,
The Miller–Urey experiment produced amino-acids, not RNA, so it's irrelevant to the discussion. Amino-acids are the "elements" proteins are made of, not RNA. You would know that if you knew even the most basic biochemistry.
This said, other similar experiments have synthetised sugars that RNA is made of (among other things). But no experiment (to my knowledge) has ever produced RNA abiotically, nor shown how RNA could replicate itself without the assistance of fairly complex proteins, which have a snowball chance in hell of ever appearing by chance. If you know of one, pray tell.
Until we can produce life in a test tube, there will always be people who don't believe it can be done, and that some other explanation must be true. And no amount of speculation will convince them.