If customers had any principles they'd ignore BA on this route. Given that BA ignored them for 10 years.
Even without direct flights, you could still book Pakistan flights via 'ba.com' using BA's alliance/codeshare partners like QR via DOH. Thats why airlines have codeshares etc. It wasn't a question of 'loyalty' or 'principles', other than the basic principle of keeping passengers and staff safe. It hasn't been safe for BA to fly to Pakistan in their view, even though I'm sure they would have liked to....... Im sure the vast majority of folks in Pakistan will welcome this resumption as a possible sign that things in Pakistan might be getting back to some degree of 'normal'.
Sadly, they'll book whomever is cheaper at the moment.
Wrong. People generally don't book BA because they're the cheapest ride in the sky. Thats BA's business model, and they would have made very careful projections on likely sales and revenues. BA made their decision to resume Pakistan flights with a great deal of research and canvassing of likely business customers.
Why would any airline show any loyalty to a route when it could just suspend it and resume a decade later with no consequences?
Why? I would have thought that would be very obvious. Airlines suspend operations over a particular route for all kinds of reasons. Take BA to Tehran for example. I'm sure BA would love to still be flying to Iran, but geo-political factors have taken their course. Im sure one bright day, the wonderful people of Iran will be able to fly BA to the UK once again.
What 'consequences' are you suggesting; that once an operator withdraws a particular route, they would be legally unable to resume it?