AMT only really affects people who make like $200,000+, right? It's a reasonable point, but I think it only applies to 5% or so of taxpayers.
If you make more than the exemption amount for your category (between 40-85K or so depending on your situation and tax year), then you should be calculating the AMT to determine whether or not you owe. It affects more people than you might think, even if it just requires the calculation to occur to see if you owe it or not.