When the "means" bcomes the "ends" - Money versus Family

Parsha Matos:

In the dialogue between Gad, Reuvein and Moshe:

The tribes tell Moshe:

טז) וַיִּגְּשׁוּ אֵלָיו וַיֹּאמְרוּ גִּדְרֹת צֹאן נִבְנֶה לְמִקְנֵנוּ פֹּה וְעָרִים לְטַפֵּנוּ:

Moshe responds:
כד) בְּנוּ לָכֶם עָרִים לְטַפְּכֶם וּגְדֵרֹת לְצֹנַאֲכֶם וְהַיֹּצֵא מִפִּיכֶם תַּעֲשׂוּ:


Rashi points out:

נבנה למקננו פה - חסים היו על ממונם יותר מבניהם ובנותיהם, שהקדימו מקניהם לטפם. אמר להם משה לא כן עשו, העיקר עיקר והטפל טפל, בנו לכם תחלה ערים לטפכם ואחר כך גדרות לצאנכם

They were more concerned about their money than they were about their children and families. This is obvious from the way they presented their suggestion to Moshe.
"First we will build corrals for our animals and then we will build fortified cities for our families."
Moshe responded:
"You need to be more concerned for the welfare of your families,
than the welfare of your livestock."

[The halacha of feeding your animals before yourself is not a question on this]

The obvious question is how can the "Dor Deah" make such an obvious mistake?

Rav Henoch Leibowitz Zt"l suggests that
the original motivation to raise livestock was in order to provide for their families.

Their original concern, the motivating concern was their families.

As it happened, they spent more time and energy on their animals than they did with their families - in order to provide for their families.
They began to see the animals for the sake of the animals themselves.
The means became an ends in and of itself.

They forgot that the real goal was their families.
Thus they seemed, in their Freudian slip to Moshe,
to be more concerned for their animals than they were for their families.