If you want to convince people who don't already agree with you, you might consider explaining why you consider "deflationary" a bad thing. Personally, I think it falls squarely in the "we could do worse, and we do" category.
After all, by exactly the same argument, why buy a computer today when you could wait and get a more powerful computer tomorrow? You could apply that logic indefinitely, except that the sooner you get a computer, the sooner you start getting value from it. At some point the balance changes, and you decide to buy one anyway.
I don't know enough about economics to say whether or not deflation is bad, but your argument doesn't hold up.