Tax returns aren't gifts. They're refunds you get because the IRS withdrew too much from your paychecks or had withdrawals from other investment accounts. While it may seem like a great thing to have a tax return come each April, you pay for it the other 11 months of the year.
“A refund means you're giving your cash flow and income to the government in an interest-free loan.” The interest rate on one-year U.S. bonds is around 1.5%, so any interest the government could hypothetically pay on that loan would be very small: about $15 for every $1,000 in your refund.