10s cooldowns are not comparable to at 70% uptime buff that if you lose 4s off you can end up dropping the buff before cooldowns come back to extend it. 10s cooldowns can be planned and are short enough that you can make sure that you know you can get them off without disruption. IV is up all the time during all mechanics, you are fettered into keeping it running through those mechanics and if one of those mechanics disrupts that flow it can totally fuck your damage. Have you even raided with frost on mythic? Because your comments really don't sound like you get how punishing the spec is in actual real raiding content?
No class is balanced around bloodlust, hence why it is such a powerful cooldown. STM is only usable in the execute phase of a fight, not the whole duration, and it brings far far more damage than IV does that is why it is cool. Because IV has such a high uptime, the spec is balanced around that, therefore not achieving that uptime means that the spec massively under performs, i cannot think of a more punishing maintenance buff attached to a spec in the whole history of wow apart from savage roar which still doesn't even come close. Again it just feels quite obvious that you don't raid mythic with this spec enough to warrant taking your opinions(which of course you are entitled to) seriously because you are missing the fundamental reasons why the spec needs changing.