Tit-for-tat. From my scarce knowledge of game-theory and world-politics it is generally accepted as the default move in these types of situations.

But well, if India sees Huawei as security threat, shouldn't they have a quite good justification for blocking them? It's not that they are outright punishing Huawei for just existing, but that there is, in their opinion, a real cause for them to fear Huawei of spying their networks behalf of Chinese government?

Although the real reason would be a lot more nuanced as usual with politics. But to me it seems a bit unfair. Russia and China (and others, sure) have effectively blocked many foreign companies in different sectors in their respective countries because of security reasons, so why India isn't allowed to do the same thing?