The problem is inflation incentivizes consumer spending. It’s better to take out a loan or make a big purchase now before prices go up. Leaving money in your savings will cause it to be eroded. In low amounts it’s very healthy. In the extreme this loop can lead to runaway inflation and that’s why consumer sentiment and inflation expectations are important to keep it in check.
Deflation incentivizes everyone to sit on their assets. There’s no reason to make a huge purchase today when you expect it will be cheaper tomorrow. You can earn real returns by just letting your cash sit. There’s basically no amount of it that’s healthy. In the extreme, consumer spending will drop off a cliff and crash the economy to the next great depression. I’m not sure there are any tools federal reserve or other banks have to combat deflation. Hopefully you can see why deflation is much more dangerous than inflation for an economy and almost never occurs in healthy economies.
Aside from all of the above, how exactly would you compel companies to lower their prices? After the market has already proven the pricing that it can bear? It doesn’t sound very free market.