Why much of the rightwing hand-wringing over the Mohenjo Daro seal stems from under-appreciation of the historical process and context:
The Vedic period begins AFTER the Harappan Civilization started declining and after the arrival of the Indo-European language-speaking pastoral tribes from the Eurasian Steppe. Therefore, any Harappan deity identified IS a pre-Vedic one. In the centuries that followed, as the incoming culture mixed with the existing culture, there were adaptations and borrowings. Some Harappan customs and practices continued as folk traditions and found their way into later Sanskrit texts. The sacredness of the peepul tree, or designs and motifs in jewellery and pottery, games of dice... This is to expected and is the natural result of mass migrations.
Excerpt from Early Indians paperback edition, Pages 203 to 205:
"Remnants of a civilization
The Vedic corpus was composed over many centuries, and it is important to remember that the discrepancy between it and the Harappan Civilization reduces over time. The later the Vedic text, the more the likelihood of finding connections to the Harappan cultural heritage. If the Rigveda was antagonistic to, and disdainful of, ‘shishna-deva’, by the time of the Upanishads, composed between 500 BCE and 100 BCE, this was no longer the case. The number of borrowed words from Dravidian languages is also higher in the later Vedic texts than in the earlier ones. There are many Harappan seals, sealings and terracotta figurines that remind one of yoga, but there are no clear references to yoga in the Rigveda. But by the time of the Katha Upanishad, there are explicit references to it. A Harappan seal shows a figure wearing a horned headdress sitting in a yoga-like posture surrounded by animals, and it has been interpreted by some as an early depiction of Siva. Many historians and archaeologists reject this interpretation on the grounds that this is projecting later-day concepts into the distant past. While that may be so, it still leaves open the possibility of a convergence between later-day ideas of an ascetic Siva and the seal images, beliefs and myths of the Harappans.
This is not surprising because over time incoming cultures often do adopt, adapt to and intermingle with existing cultures, and the Arya and the Harappans may have done the same to varying degrees across cultural domains and geographic regions. And, of course, a lot of the cultural continuity from the Harappan Civilization is reflected in popular practices rather than in the Vedic corpus.
The way houses are built around courtyards; the bullock carts; the importance of bangles and the way they are worn; the manner in which trees are worshipped and the sacredness of the peepul tree in particular; the ubiquitous Indian cooking pot and the kulladh; the cultic significance of the buff alo; designs and motifs in jewellery, pottery and seals; games of dice and an early form of chess (dice and chess-like boards have been found at multiple Harappan sites); the humble lota which is used to wash up even today; and even the practice of applying sindoor and some measurement systems – the ways in which we carry on the traditions of the Harappan Civilization are too many to count.
A vase discovered at the Harappan site of Lothal in Gujarat has a painting that shows a crow standing next to a pitcher with a deer looking back at it, seemingly depicting the tale of the thirsty crow in the Panchatantra. So some of the tales we tell our children may have been the same ones told by the Harappans to their own children.
What ended around 1900 BCE, therefore, was the power structure that had kept the civilization going for over seven centuries, and with it went the script, the seals, the standardized bricks and some of the ideology as well – such as the unicorn. But many other things that are part and parcel of the common man’s life continued, along with some of the philosophical and cultural underpinnings of south Asia’s first civilization..."