Because all aqueous solutions are uniform in composition
homogeneous means the same or equal. (homo = same)
Normal milk is is not homogeneous, the lighter thicker cream "settles" or rises to the top. The cream is made up of fat molecules which do not dissolve into the water solvent of the milk.
Homogenized milk has been vigorously stirred so that the fat molecules of the cream are suspended evenly throughout the mixture of water, and cream. It is not a solution but it is homogeneous.
In a true solution intermolecular bonds are formed ( not chemical bonds) that cause the solvent and solute to be evenly distributed in the solution. As the amount of solute in any part of the solution is the same throughout, the solution is homogeneous.