As plain as the title reads. If you pop berserker buff with hatchet then switch to another weapon, you should be entitled to the duration of that buff. This should even include the PASSIVE buffs from your secondary weapon.
Why? Consistency.
Why is it fair to drop an ice pylon then switch weapons?
If you’re going to make it so that I can’t feel smart/powerful with my combination of weapons then go ahead and make ice pylon despawn if you switch off of ice gauntlet. Alternatively I’d much rather enjoy having the benefits of both weapons.
How much more creative and powerful would your builds be if you had the benefit of passives for your secondary weapon?