Draw Phase irrelevant?

No, seriously. Why do so many people wait until the Standby Phase in order to activate their traps/quick-plays that they intend to use literally as soon as possible? Did they all forget the Draw Phase is a perfectly legal time to or . . . ?

I don't know I assume its because we are more use to effects during the stand by phase (ex. Wind-Up Rabbit and Treeborn Frog)

it's just so.. weird ._.

It's optional to wait until the SP.
Most people wait for the SP because of some cards that can only be activated during the DP e.g. Drop Off, Drastic Drop Off, etc. so there aren't any misunderstandings.
Overall it doesn't really matter if you use your effects in the DP or SP, I guess it's just a trend for everyone since we all use our cards in the SP, and since the turn player has priority of using something before the non turn player, usually the non turn player wants the opponent to declare he's ending the SP before activating anything since.... tactics. They might blind MST before you use your iron wall in the SP, and that all goes in your favor.
It's not something big or relevant against good players (not yet at least), but everyone tries milking every little drop of their chance of winning.

The kyonaru has spoken.