All airline systems are rubber band and cogs, frankly, and it's their own rubber bands and cogs

And the market is too small and idiosyncratic for someone to come in and develop a standard system such as an Oracle Financials or Salesforce CRM - not that these don't have their issues. The recent wave of mergers in the US have proved how disastrous the IT integration piece can be (UA/CO was stunningly bad).
The only way to make it work reasonably well would be to literally fold VS into DL wholesale, IM/RM, awards, FFP etc etc. It may come to that I suppose, I'm just glad I booked myself onto a couple of VS trips before it happens

Having said that, I totally agree with Slinky on this one, there's a bit of misrepresentation of Tata going on. Their problem is size, IMO, in that large consulting shops tend to have objectives of their own (other than customer success) driving what they do, as well as a harder to assess, more diluted pool of skills to offer. They bring a name tag reliability that is a bit harder to assess with smaller consultancies. I've seen very similar issues with CSC, Deloitte and PWC, to name a few. Where they did their work seemed to bear little relevance to how they did it: big guys messed up even when they placed a whole bunch of people in house, TBH. And the cost of a big consultant bringing their people in your house for a project is eye watering.