why stack column is giving me the column's names instead of the column values as a result?

[#1]

I am traying to stack columns and the result are the column's name instead of the values, why?

[#2 · Accepted solution]

2 columns should be generated.
One with the colum names in the rows and one with the values   .

Just  think about the inverse: split.

To know which value goes to wich column, you need a column with the target column name.

If you don't need this column, you can delete it.

[#3]

Like @hogi said it is there to allow you to identify to which columns those values did belong to and you can easily delete it if there is no need for it

Using JMP > Reshape Your Data > Stack Columns in Data Tables > Example of Stacking Columns into a S... 

In the Preview pane, the Label column represents the Source Label Column that identifies the source of the data. Its values are the column names in the original table from which the stacked values originated.