A lot of people are expressing the sentiment that the government should have exposed and punished them, but quietly kicking out spies is par for the course. When this hits the media it's generally a bad thing.

Everyone spies on everyone. Everyone knows they are getting spied on. You have to be careful how you respond because you don't want to escalate. You make it known to the other government that they have been caught and you gently move them on as a show of good will. When your spies are caught abroad breaking laws you want them to do the same for you. Now that this has gone public, India lose face, which could cause future tension. Also, sometimes finding spies on home soil can be useful if you let them think they haven't been caught.

The average citizen thinks you can use playground rules here, but espionage is all about being subtle.