I didn't downvote you, but here is what I think may have motivated the downvoters:
Assuming facebook is using some form of SQL doing that would be as simple as "SELECT INTO OUTFILE" with the appropriate clauses, so this doesn't add anything whatsoever to the threat from the direction of facebook.
If someone manages to hack in to your facebook account it's become marginally easier, but a well written bot would have a lesser problem digging out your profile than you as a user would, so facebook just made it a bit easier for users to get at their own data at 0 cost to them, and with a negligible security risk in the case of a compromised account.
That does not detract from the fact that I think that this is largely a PR move and that any real benefit is quite small, other than for those people that would like to have their data in several places.
In those cases facebook probably comes out ahead because you now only have to upload to facebook to be able to export it to another service (I don't think it will be long before the first 'import' utilities will be made).