An argument you hear a lot, particuarly from Keynsian economists is: bitcoin is bad because it's deflationary like gold.
In the past when we were using gold, like during the Civil War, we couldn't pay soldiers so we went to greenbacks (paper money like today). That allowed the soldiers to get paid so we could continue to fight the war. Gold obviously has a physical practical limit that can be traded and transfered. When a gram becomes worth so much it buys a house that makes other purchases of food and bills become impractical and people stop buying, and when building a billion dollar construction project moving it and protecting it has another set of problems and overhead. Bitcoin does not have the division problem--a single coin can be divided into pieces 10^8 pieces as the code currently works. That can also be changed in future versions to be divided even smaller. Ie, when one bitcoin can buy a house, you can just pay 0.0000001 for your stick of gum. So, we are then left with the argument, "Oh My God people won't buy because of the psychology that 0.01 coin today that currently buys a pack of gum being able to buy a car in the future." But, that's almost true now with savings and stocks and people still spend their money today and go into debt. Everyone knows if you save starting in your early 20s compounding interest it will be worth a ton more in 10 years, 20 years, etc.
Loans clearly have issues in a deflationary system. If you loan someone $10 today and that's worth $100 tomorrow how do they ever have a chance to pay it back? Payback would have to be on some growth rate where you owe "less" the longer the life of the loan with some interest built in. Venture Capital also would have issues, but if the rate of return on investments is greater than growth of the currency price that wouldn't be an issue either and one would expect it to stabilize over time.
Inflation is built into the current model to encourage investment and prevent concentration of capital. Clearly, given the wealth divide that isn't working (blame exploitation of 3rd world or robots). The argument from the anarcho-libertarians and socialist-libertarians is to try something new.