The MITC is a hugely regressive policy.
Really comes down to how long you intend to stay in the home.
How do you figure that? What about cost stability? What about not losing 100% of your payment (that is, retaining some as equity)?
I'm not saying there is always an incentive; some markets favor renting over buying in spite of the MITD. However, saying the only reason buying is financially attractive makes no sense.
Edit: corrected C (credit) to D (deduction), since it is technically correct and makes a big difference in it's usefulness.
In what world? I have never seen a market where rents were below P&I for a comparably-priced house[1]. I would love to see a real example of this.
[1] Note that this does not automatically make buying better, as rent factors many costs P&I does not.