I know it may sound harsh but the truth is: We should not tolerate tantrums...
...we should tame them.
Do you know what the result of the 1st tantrum ever was? Let's read it together (emphasis mine):
Genesis 4: 5-7 - Time passed. Cain brought an offering to God from the produce of his farm.
Abel also brought an offering, but from the firstborn animals of his herd, choice cuts of meat.
God liked Abel and his offering, but Cain and his offering didn’t get his approval.
Cain lost his temper and went into a sulk. God spoke to Cain: “Why this tantrum? Why the sulking? If you do well, won’t you be accepted? And if you don’t do well, sin is lying in wait for you, ready to pounce; it’s out to get you, you’ve got to master it.” (The Message)
Tantrums are destructive - not just when displayed by children. God clearly warned Cain (who was an adult), not to let the tantrum "destroy" him - but he disregarded God's warning.
We owe it to our children (& maybe to some adults around us too) to instruct/advise them on the destructive path tantrums can take them to. I know that sometimes children want to "vent" but we must help them control their emotions and the expression of those emotions* so they do not destroy themselves &/or others. May God give us wisdom on how to tame & terminate tantrums.
Prov 14: 17 - People with a hot temper do foolish things; wiser people remain calm. (Good News Translation)
Prov 16:32 - Controlling your temper is better than being a hero who captures a city. (Contemporary English Version)
Prov 25: 28 If you cannot control your anger, you are as helpless as a city without walls, open to attack. (Good News Translation)