Planking with Pit is far less gay and far less defensive than doing an infinite with DDD. You can fight a planking pit. You can read him, you can still PLAY. He is just using his options to minimize risk while still attacking you. Thats exactly what infinites do. They minimize the risk of getting countered to 0 while still attacking their opponent.
Getting the lead back from metaknight or pit while they are planking is much more likely to getting out of DDDs infinite.
The situation you described is a somewhat wrong comparison. You can't compare Planking & Infiniting. But you can compare planking with grabbing. Planking actually is the action / the cause. What happens when you try to fight against it?: You probably get gimped.
Grabbing is the action / the cause, when you get grabbed: You probably get infinited.
The correct comparison must be: "Beeing in an infinite AFTER fighting getting grabbed" is the same like "doing an up-b but can't get back on stage / edge AFTER fighting planking"
While infinites indeed minimize the risk of getting countered to 0, successful gimps do this as well.
And now think back about planking & grabbing.
Planking - Defensive -> YOU have to do something to stop someone from planking
Grabbing - Offensive -> Your oppenant has to grab you (!) YOU need to stop him from doing so
Throwing out grabs gives your oppenant openings, which can be exploided.
Going out to stop someone planking, just leads in you beeing at a very high risk / very low reward situation, while it is a very low risk situation for the other.
To avoid getting grabbed you need to be careful, indeed, but it's not the same like "you have to go into a high risk situation".
I hope it's understandable, English still isn't my first language :/
I somehow feel so bad discussing in English
(Eeeh, I forgot that I wanted to stop discussing in this thread ... xD well stupid boringness
)