Because there are some difference between apical and intercalary meristem.
they are:
Apical Meristem: Apical meristem is Located at the growing points of the stem, roots, branches and in growing young leaves near the tips of stems and axillary buds.It enables the root and stem to grow by increasing the length of plants.
Intercalary Meristem: It is located at internodes or stem regions between the places at which leaves attach, and at leaf bases, especially of certain monocotyledons.The cells of the intercalary meristems are active and continuously form a number of new cells.