Imagine an underground pipe of unknown length and extent. One opening of that pipe is found in India and another in Europe.
I was going to write something similar today.
I'll offer another analogy.
In the 18th/19th century, guys like William Jones, Thomas Young, Franz Bopp, etc. found the similarities between Sanskrit and European languages and thus established the "Indo-European" school of language and race studies. Many European philosophers spoke highly of Vedas and an interest developed. Earlier many Germans wanted to rid themselves of their Judaic past, so they hopped on to the Sanskrit bandwagon.
Consider a scenario, where a prisoner (Germanic people) is tethered to a donkey, a history dominated by Judaic past and is being dragged away against his wishes. The prisoner just wants to dismount this donkey but can't on his own.
So instead the prisoner decides to throw a lasso around a much more ancient tree (Vedic tradition) and use that to pull himself away from the this Judaic donkey. The Germans went further along this plan than the good Christian people in Britain and USA, etc. were willing to see. So even though in WW II, the Germans were thoroughly defeated, this rope remained between the Europeans and the Vedics.
Now the Christian West is comfortable mounted on their Judeo-Christian donkey, but this rope tied around their trunks and the Vedic Tree, is something that is tearing them up. As ManishH put it, the linguistic connection between Sanskrit and European languages is strong. The rope is strong. You can't cut it anymore. The easy way out for them is to uproot the Vedic Tree from India and pull it along and let it be dragged by the donkey also.
But along with the Vedic Tree, came another baggage - the Indics. And nobody in Europe wanted the colonized enslaved half naked dark fakirs as their equals and sharing the same heritage. In fact, the white Europeans thought they could take all the rich Vedic heritage, and be able to ignore the dark Indic completely. After all India was a British colony to be controlled and ravaged at the pleasure of the Brit.
But this Vedic Tree belongs to Bharat and the Indic monkey is not going to let the Europeans uproot it or rob it from him. The Vedic Tree is first and foremost the heritage of the Indic Monkey that sits in it.
So instead of having all the ancient Vedic gold at the end of the rope, they have a loud Indic monkey pulling at it as well.
The Europeans are stuck in their "Indo-European" situation and they have only themselves to blame for it.
All these Indology studies, AIT, AMT, palaeolinguistics, etc. are simply the Europeans tugging at that rope. One would also see the Europeans trying to tickle the Indic monkey to let go of the Vedic Tree.
One sees Europeans planting other trees like Islam and Xtianity in India, adorned with fake flowers and artificial scent, so that the Indic monkey can jump from the Vedic Tree on to those other trees. One sees the West luring the Indic with other sweet fruits of Yuppie culture, hoping he forgets the taste of his own culture. One sees English language plants being planted all around the Vedic Tree, so that the Indic Monkey is overwhelmed by them and forgets Sanskrit. Sanskrit is being made into a dead language in India, and in the West they are opening more seats to study Sanskrit and munch on their new PIE.
PIE is an effort by the Europeans to say the grapes are sour. They can't get the Vedic Tree so they are building up another tree of cardboard someplace else, and saying that the Vedic Tree was sown in Bharat using the seeds of that cardboard tree. But the rope would not cut. So PIE is their effort to loosen the rope to the Vedic Tree, something they tied themselves. For the PIE Tree, they need to cut the Vedic Tree's branches generously to use them to adorn their PIE Tree. Without those branches and leaves, the PIE Tree would simply look naked and be seen for what it is - a cardboard tree.
But the Indic Monkey is proud of his Vedic Tree and is not going to accept that it grew from the seed of a cardboard tree called PIE.
The Witzels of the world are frustrated that the monkey would not let go of his Vedic Tree nor would he accept their cardboard tree, or let them rewrite the etymology of Sanskrit.
As archaeological, genetic, geological, astronomical, literary evidence mounts up in favor of the Indic Monkey, the European bulldog does not know what to do. Linguistics and Horse is their last valiant effort to confuse the Indic Monkey into accepting the European confiscation of the Vedic Tree. That is why they use the highly technical jargon. It is going to get even more technical.
It actually reminds me of the Panchatantra tale of "Brahmin and the Three Thugs". The thugs kept on telling the Brahmin that the goat was some other animal - dog, donkey, calf etc. until the Brahmin got scared and let go of the goat for the thugs to feast upon.
If the Europeans lose this tug-of-war against the Indic Monkey, they are $hit-scared that they would have to follow the Indic monkey, where ever he goes, something that seems more and more likely as India recreates its prosperity and military strength.
If the Indic Monkey says sit, they will have to sit, and if the Indic Monkey say roll over, they will have to roll over, and if the Indic Monkey says Dharma, they will have to say Dharma.
OIT means the Indic Monkey owns the European history, and that is a very difficult proposition for a White racist to swallow! But hey! They asked for it. They were the initiators of this tug-of-war!