Why is 1:144 scale used for plastic models? Why a modeler originally choose 1:144 scale to create a plastic model such as GunPla? Why not choose 1:100 or some other number that can easily determine the size of the model from the original size?
(Didn't you ask this exact question of SF&amp;F yesterday?)

Traditionally, toy makers have used a 1:12 scale when building scaled down model of real objects, such as dollhouses. This practice pre-dates the metric system, and made it easy to scale down measurements because, at 1:12, one foot becomes one inch.

Now, suppose you wanted to build a dollhouse, and inside it, you want to have a dollhouse. To do that, you'd have to scale down your 1:12 model house by another 1:12, to give you 1:144. This is why 1:144 is sometime's called the "dollhouse's dollhouse scale".

Since 1:12 and 1:144 were already well known and popular by the time anime miniatures came around, the first people to make such models were already familiar with it, and they used it. After that, it's mostly inertia.