Ok I think first 2 posts are both wrong and right
Yes seedlings can survive outside, but yes they are fragile too.
Yes they wouldn't of survived naturally if they couldn't grow outdoor, but the ones that germinated best in the wild probably started a little shaded in the undergrowth- not in some cleared full-sun position.
Also though, who says it's not growing? The op didn't... but he also didn't mention how old it is either. More info on that would be useful before conclusions are made.
As for the burnt looking tips- that could be a few things. It could be too much radiation from the sun at such a very fragile age (just sprouted) but it could also be to do with the soil mix. Is it pre-fertilized? Seedlings are very fussy about what they sprout in.
More info is needed, but I would also advise you not to put the sun in full sun all day until it's a bit bigger or use some kind of shade cloth. It's not just the sun too really- if it buckets down rain on a seedling that small it that might even snap it... I personally learnt that one some years ago.