Why are people so "anti PMI"?

I know it's not a tax write off but really what's the big deal? I recently bought a house (8-08) and mine is $60 a month=$720 a year. I did a FHA loan and only put down 3.5%. I felt is was better to keep the rest of the money I had in savings than use all of it for a down payment especially since it would only save me $60 a month. If I was able to buy a house for a little more a month than I was paying for rent, still keep money in the bank for a "rainy day", AND get the tax write offs of home ownership isn't it a good deal?