A restraint kit is standard equipment these days, crews are trained to deal with unruly passengers and this sort of thing happens on most airlines.
Scoot had a husband and wife fighting in the cabin a few months ago.
I considered using Air India business class for a trip to Europe as the fares were cheap and the miles count at 200% when credited into their own frequent flyer program (125% into another Star Alliance FFP). You can easily get a Star Alliance Gold card with a couple of long trips. There would have been a long layover in Delhi on the way back but I was going to stop over and see the Taj Mahal.
The wife wasn't too keen on flying with them and getting the India visa was a pain so I ended up with a Middle Eastern airline instead. I will consider them for future trips, hopefully things will improve with Star Alliance membership.