Why Can't Lipids Dissolve In Water?

Because  lipids are fat molecules, fats are like solid oils, in a general sense, look into the reason oil and water don't mix and you will have your answer.
Basically, oily things like lipids are not polar, they have a relatively non-electrostatic surface, whereas water and polar molecules have residual charge spread around different regions of their surfaces.

The more carbon atoms, the more water-soluble is not easy to tend. Lipids have a lot of carbon atoms ,so they can't dissolve in water .

Lipid itself does not dissolve in water, they must be combined with proteins to form in order to dissolve in the form of  proteins exist in plasma.