BA, like many long established corporates has a 'culture' and each new generation of staff who join find themselves unable to break through that culture. I have seen this in many enterprises, not just airlines.
It is all part of the human desire to keep things the way that they were and difficulty in seeing what they might become. Which is how old companies die and new ones are born. In the (I think) late 1970s, British Rail experimented with ways to reduce cost of their multiple diesel units on small routes. They took a body from a coach and put it on bogies (obviously more complicated than that!) but it didn't work. Many years later, it came out that some of the senior BR men had thought, "It didn't look like a train" Sums it up.