Lila, I think there are a couple of possibilities. The lineage of a family came through the sons of a man, and the inheritance typically stayed with the sons. An example of this is the land owned by a man. His sons would have been left his land. Had he no sons, his daughters would have been left the land, but this land could have theoretically become the land of another tribe had the daughter married outside of her tribe. This is addressed in Numbers 36:8:
Numbers 36:8 Every daughter who comes into possession of an inheritance of any tribe of the sons of Israel shall be wife to one of the family of the tribe of her father, so that the sons of Israel each may possess the inheritance of his fathers.
The Bible tells us in Deuteronomy 21:17 that the firstborn son is the beginning of his father's strength.
Deuteronomy 21:17 But he shall acknowledge the firstborn, the son of the unloved, by giving him a double portion of all that he has, for he is the beginning of his strength; to him belongs the right of the firstborn.
This isn't the only place that a firstborn son is referred to as his father's strength. I just realized, in this context (and all contexts, I suppose) Jesus is the strength of the Father.
I think it was certainly a sign of strength and blessing for a man to be blessed with sons. That doesn't mean he didn't value his daughters, but if a man had only daughters, his wealth could become that of another family upon his death.
When scripture mentions that a man had only daughters, it probably is indicating it was an anomaly. I think a man would have likely continued to have children, had his wife or wives been able to, until he had a male.
I think this is one of those topics that can make one think that the daughters were of no value, but I do not believe that is what the Bible teaches. We see an example of a valuable woman in Proverbs 31 - if a woman was of "no value", such a passage would not be present. Psalms 144:12 is a place where blessings are spoken on the sons and the daughters. I think this is simply a case where belongings passed through sons, even in the case of children (after all, a man 'gave' his daughter away at marriage), and a man with no sons would likely not have a documented lineage to speak of, and as said above, his wealth would be passed on to another family, albeit in his same tribe.