Someone in the situation you describe wouldn't be able to take work hours to go vote, either. Not to say there aren't people living that reality; I'm sure there are. The question is whether such a measure actually impacts them or not, which depends on how likely they were to have voted before any sort of ID requirement were implemented.

I think people, no matter their circumstances, find a way to do the things that are important to and required of them. Whether it's finding the time or the money, everything comes down to priorities. I think it's fair for proponents of the photo ID requirement to expect that voting ought to be important enough for someone to be willing to go to some effort to achieve it; I also think it's fair for opponents of the photo ID requirement to point out how it might disproportionately affect certain segments who can less easily absorb/overcome the additional complication for lack of a better word.