If it's pointless then why do you care if I do it or not. Just let me be.
If it's pointless don't do it. you're wasting my time. I'm playing the game too, and if time is called in the round, I don't want to be the one stuck with only one extra turn because you took too long on your previous ones.
I might want to declump for any reason in the world. I might even be superstitious about it and not like my rare candies next to energies. Maybe I think cleffa looks extra cute sitting next to an Elm's training method when I search. It doesn't matter.
Then when our game is over, you can take your deck, and you can put your Rare Candies on opposite ends of the room while you perform a Ritual over your Professor Elm's that are Training your Cleffa. But while our game is going on, you do what the cards to tell you to do and that is final.
All that matters to YOU is that my deck is properly shuffled and I haven't taken more time that is allotted to me when I perform a search.
But you're not searching. When you decided to rearrange things, you've deterred from Searching in order to make things look pretty. It matters to me when you waste my time and the game's time so that you can be satisfied how something looks for the next 3-5 seconds.
I'll decide if what I do is "pointless" or not.
Sure thing. Just don't be wrong when you actually get down to deciding.
Also, if for any reason you feel your opponent's shuffle isn't adequate enough, then by all means ask to shuffle it yourself. There are rules for this, ya know. No player should ever feel that their opponent's deck isn't properly shuffled at any point in the match. It's your own due diligence to shuffle if you feel your opponent isn't doing a good enough job shuffling their deck.
Shuffling is not the issue. The issue is the attempt to either Cheat yourself into a better advantage or to waste time.