One: people that are doing this are likely to have already been bad bosses. I don't think this changes anything.
Two: I work for a large bank. My director, on a town hall, told us they do understand that not everybody will be able to focus on the job as before and that they expect us to spend less time actually working and be unavailable more often. Then he URGED us to actually do so. To take time off, to deal with family problems first. He wanted us to know it is ok and that they will allow it without deducting pay so that we don't have to worry about our salaries.
I am pretty sure there will be people that will abuse this. You know what? People who do this probably have already been bad employees so not much is lost. Most people I know to be good employees feel very happy about this as a convenient option and do whatever they can to use it as little as possible. I see this as an investment that is most likely return in other ways, employee happiness, retention, engagement from the staff you really want engaged.