What a disproportionate reaction from Github. They could simply block network access from Iran to make it easier. Otherwise, blocking without giving warning is

What a disproportionate reaction from Github. They could simply block network access from Iran to make it easier. Otherwise, blocking without giving warning is wrong. Even banks give warning and deadline to their clients before closing accounts that are linked to sanctions. Why Github blocked the entire organization without proper communication and deadline to fix or clarify the issue?