Inflation is a necessity IMO.
Look at the opposite... deflation... if there's constant deflation, why would you buy goods now, except for the necessary goods like food etc? You want a new pc/laptop... but you could still do with this one... and you know that waiting 1 more year will mean it's cheaper.
In simple terms, deflation is when your dollar will get you more later than it does now -- that the value of the dollar effectively goes up with respect to the good or service you're purchasing.
Computing technology (desktops, servers, laptops, tablets, phones) gets cheaper for the same computing resources over time. So $1000 spent today gets you less than $1000 spent 5 years from now. Technology is a market in which what you get per dollar is effectively deflationary, so by your logic, why would anyone ever purchase technology?
I'm not going to wait 5 years to buy a new cell phone even though the one I have is fine. Why? Because I want a better one and even if I wait 5 years, I could wait another 5 and get something better? When does it stop? It doesn't, so no matter when you buy, you could have waited and get more for your money, but plenty of people still buy new cell phones regularly.
Part of the answer is that those goods or services provide a ROI, so the sooner you purchase, the sooner you get benefit. For items that don't provide a ROI, there's the desire for instant gratification.
This line of reasoning that with deflation, no one would purchase is silly. If food is cheaper 5 years from now, I'm still going to buy it today. If shoes are cheaper 5 years from now. If a vacation is cheaper 5 years from now, etc, etc.
This desire (or in some cases, necessity) to have things now despite them being cheaper in the future does not eliminate people's desire to pay more for them now. It's the same reason people pay more for faster shipping or that people buy things on credit (ignoring those cash strapped buying true necessities). Deflation does not spell the end of the economy, despite what pro-inflationary people would have you believe.