The select into/bulk copy option is mainly to make bulk inserts/updates go smoothly. When doing a huge insert, the transaction log needs to continuously grow and it might not be able to grow fast enough.

Imagine inserting a million rows, but only allowing your transaction log to grow by 100 MB. It probably won't grow fast enough to keep track of the inserts. So it fails.

SELECT INTO/BULK COPY ignores the transaction log completely.

-SQLBill