Why are companies so biased against employees those who come late and work late as compared to those who come early and leave early?

Why is it okay to leave early but not so much to come late instead?

After some of us ignored repeated warnings, we've been told that anyone come after 10:30am will be marked half day absent.

So, if they do so, I'll sit there in office playing Fifa or Table Tennis, and not work until the second half starts xD

The reason for such biasness is that the daily stand-up is at 10:30, even though more people wanted it to be after 11. They even took a vote. And yet it was ignored (funnily initially more ppl voted for 11 initially and somehow some of the votes changed for in favor of 10am... Now slowly, because half the team wouldn't be on time, it's shifted to 10:30am.

And funnily, I'm already serving notice period in this company.