The value of it rises and the feds may insure against drops in value of your house. You can use it's tax free proceeds to avoid tapping into taxable IRA withdrawals, with all it's side effects of raising medicare premiums, etc. You can avoid locking in capital losses on stocks, and have income to wait for return of a bull market.
So I am curious whether someone who has no specific need for such a line of credit should get one, and when. It now almost sounds like a gov't giveaway program that leaves you behind if you don't join, but maybe there are some pitfalls for even the most modest involvement?