Why is the concept of enantiomers big contained by the pharmaceutical industry?

Why is the concept of enantiomers big contained by the pharmaceutical industry?
because some reactions can hand over a racemic mixture. If one enantiomer is the active chemical you are looking for and the other is adjectives, then you are ok, but if the second is toxic, afterwards you have to purify for the desired enantiomer.
You can judge of molecules as having a "handedness". If a antipathy produces two compounds that are the same, but one is a mirror symbol of the other (just like your not here and right hands). In some cases a left hand molecule might be beneficial, while it's right handed twin could be poison! I believe thalidomide is a virtuous example of this.