Thoreau very wisely wrote that ‘A man is wise with the wisdom of his time only, and ignorant with its ignorance’. When people draw conclusions and make observations or generalizations, it is on the basis of evidence available to them and in a framework prevalent at the time.
Max Muller worked about 150 years ago. Vedic studies were new at the time; much of the corpus had not yet been translated or analyzed; and archaeology of India was still into the future. There was thus hardly anything to constrain speculation. The Norwegian Indologist Lassen suggested that the Sarasvati river of the old Rigvedic mandalas was the old Ghaggar in Haryana. Max Mueller accepted the hypothesis and popularized it. In contrast, the Germany-based Hillebrandt identified Sarasvati with a river in South Afghanistan. While Hillebrandt has been ignored, without going into the arguments proffered by him, for reasons of convenience, the Lassen-Mueller hypothesis has not only been accepted but elevated to the level of a gospel truth.
On linguistic grounds, Mueller concluded that the Aryans, as a branch of Indo-Europeans, came from the northwest. By placing Sarasvati in Haryana, he assumes that the Rigveda was composed in India. European scholars held the Puranas in contempt; they would not take note of the long-held belief that Sarasvati was an invisible partner of Ganga and Yamuna. But today’s Indian scholars must address the question.
Rigveda refers to Indra as purandara , the destroyer of pura (forts, settlements, etc). Mueller assumed that these pura must be the earlier Indian settlements and concluded that they were destroyed by the invading Aryans. In the colonial framework, it was very convenient to believe for the British to see Aryans as invaders so that their own forced entry into India could have a precedent. But it did not suit them to have Rigveda composed outside India. This would have worked against the colonial premise that while upper-caste Hindus and Europeans were ethnically the same stock, Muslims were different by definition.
It should however be kept in mind that the key question is whether the Aryans came from outside or not; whether there was an invasion or migration is a matter of detail. There is now a near unanimous consensus that the Harappan civilization was weakened by a very prolonged drought ( which affected a vast area in the world) so that the incoming Aryans did not create political vacuum by invasion but filled one created by ecology.
Fake scholarship is being created on ancient India. It is fake because it is not consistent and rigorous. Max Muller is accepted (Ghaggar) or rejected ( invasion/migration) as per convenience. This is unfair to scholarship generated and evidence collected since his time.
At the current level of knowledge, literary evidence from Rigveda and other texts on the one hand and the archaeological evidence on the other constitute two distinct streams that do not interact. Old literary evidence is not backed by any explicit archaeological evidence nor does the archaeological evidence have the benefit of widely acceptable decipherment of the script.
The inherent uncertainty of the available evidence must reflect itself in the conclusions drawn on their basis. Any working hypothesis linking the Vedic corpus and archaeological evidence must remain consistent with the contents of the sacred texts.