Goop Gas Attack isn't as strong as you think.  When you use it, it shuts down power for their turn only right? Right

 

All Pokemon Powers stop working until the end of your opponents next
turn.

 

Well the END of my oppenets NEXT turn will be right after MY turn.  That will technically be their "next" turn.  They wouldn't make the card stating:

 

All Pokemon Powers stop working until the end of your opponents this turn.

 

So it will disrupt powers like:

 

Raindance, Damage Swap, Energy Trans, Energy Burn, Prehistoric Power but not powers like Invisible Wall.  ((It will stop it for your turn, but not on theirs))