So, why does the Mastermind ATO set suck?

No, that's not at all what he wants. He's talking about an enhancement like a hami that helps all the secondary things a henchman could benefit from. There was no mention of an aura.

Not really. He's asking for a multi-aspect enhancement purely for MM pets.

Saying that that makes it a "slottable version of power boost" would make the blaster acc/dam enhancement a "slottable version of aim".

Power Boost is a power that buffs the user for the majority of their secondary effects.

What he's asking for is an multi-aspect enhancement that boosts the enhancement values of all effects that aren't dam/acc/rech/end-redux and that can only be slotted into MM pet powers.

This would be for pets that use heals or give a buff. Normally if you want to enhance those aspects of a pet, you need to skip part of the pet set. Or not use a set at all and enhance the pet using HOs. With such an enhancement in the set, you'd be able to use the entire set on a pet that's both damage and support without failing to enhance any particular aspect.

For an MM with of defense buffs for his pets, such as bots/FF, it's actually better to try to keep the aggro on the pets. Therefore, BG mode is much less useful to them overall. The pets will end up having much lower survival rates when BG mode is used heavily.

Oh, I'm gonna have to disagree with that. Assuming the MM itself also has decent defense, like my bots/traps does, it's survivability in bodyguard still far outshines it's survivability otherwise. Proper management of the pet's positions (to avoid auto-hit or high to-hit AoEs/patches) and a bit of taunting from the MM makes the pets unlikely to take any non-BG damage. With the MM equally protected by defense, they become highly unlikely to die in any situation. Grab aid self for when the MM is hurt (since defense should allow you to get it off before you are hit again) and you find yourself tanking AVs easily.

Obviously, it takes a little more pet management, but the payoff is significant. MaxHP is helpful somewhat in this situation, as it only improves survivability for the (hopefully few) hits the MM does end up taking.