People who have a high amount of debt relative to income (generally the poor, the middle class, governments) benefit from inflation, not deflation, as they can spend full value money today and pay it back with diminished value money later.
Your concept of the poor as savers benefitting from deflation because they save money and stick it in the bank directly conflicts with the core definition of "poor".
But they keep having to pay more for Stuff. In other words, their purchasing power keeps decreasing, unless their wages rise to compensage for inflation. Deflation "means" an increase in purchasing power, which means getting more stuff for your money, which is.. good? What's not to like?
It only makes sense to save when there is enough income that the risk of losing savings from a) bad investment or b) inflation is lower than the expected payoff.
But saving makes sense even just to prepare for unexpected expenses. We're not talking about hundreds of thousands of dollars here, in most cases, it's not even tens. Barely scraping by might be a bit of an alien concept to someone pulling in $250K/year from programming.