Sure, deposits make up a significant portion of banks funding. But there is no "right" of an individual to expect to receive a certain return.
Fair point about cheap credit replacing bank deposits. Although this is not as sinister as you make out.
IRs are reduced to stimulate the economy. Bank deposits then become less attractive and funds are withdrawn. So the CBs are providing banks with liquidity to again help stimulate the economy. The investors taking their funds out of bank deposits are also contributing to stimulate the economy be deploying the funds in more productive assets than sitting in a bank.
As for rewarding savers. So now you want the government to intervene to reward savers? Which is the opposite of leaving markets to their own devices.
