Do you find writing dead code useful?

Some says "If you have 2 logic to do some operation then instead of making other logic code commented or removing code make it dead code as it will not affect the operation."

Example:-

if(true){
    // logic - 1
} else {
    // logic - 2  // dead code
}


Is it true?



I usually do not write dead codes instead I just remove the second logic. 

IMO, it is worse than pointless.

In addition to being a waste of time, it gives you (or the next guy) the illusion that you've got some code that will work if you change true to false.  It is only an illusion ... unless you test it.

And if course, it is clutter that makes the code harder to read.
