There comes a point when kids can no longer be used as an excuse for poor work performance.
No doubt about it, being an involved parent and a decent employee at the same time can often feel like an impossible balancing act. The standard workday was not designed with parenting in mind, and that is doubly the case for many high-pressure jobs. In some industries, there is only so much flexibility that can be expected while still being competent enough to deal with a workload.
It isn’t fair, and keeping on top of childcare while working should not have to be the battle that it frequently turns out to be. Nonetheless, parents with jobs have to find a way to make it happen. They are the ones who chose to add the responsibility of children on top of all their other tasks.
For a manager, somebody who has issues at work because of their kids can be very difficult to deal with. They may have empathy for the fact that they are struggling, but at the end of the day, their main responsibility is ensuring that their employees do their job properly. If family is interfering with that, they may have to take harsh measures.