It just means that one business is less profitable than another, that's all. As long as profit earned is above inflation (mind this), the business is sustainable in the long run. Which will never be the case if it continuously suffers losses due to deflation, whatever interest rates might then be. I don't really understand why you are trying to argue against this simple fact.
In deflation the business can save more money and whilst many competitors will compete with it, this could bring true capitalism with better and better products.
In inflation the banks eat your money by inflation and also by debt that you hold. Many companies hold alot of debt, if interest rates were to rise, they would all go bankrupt.
What kind of companies (save for financial institutions indeed) you mean that hold debt? In fact, companies usually borrow money from banks to finance their working capital or make investments into their fixed assets (property, plant, and equipment). Also, expand more on how businesses can save more money in deflation, through laying off their stuff, maybe?