I think part of the problem is being attached to hotels and being unwilling to disappoint any customer. If you're going to run a decent steakhouse you need to focus all the attention on the grill. It's no good having a station where somebody is microwaving disappointing "pub classics" or "italian food". If the couple in room 46, or the people who staggered in to use the bar want food then they have to eat steak/grillfood or go somewhere else.They should be able to maintain the three brands done properly, Brewers Fayre is cheap family friendly pub classics, Beefeater focuses on steaks plus some other dishes, Bar + Block is a premium city centre steak restaurant.
Mitchell & Butlers have managed to keep lots of brand identies very well, Stonehouse, Harvester, Toby Carvery, Brown's, Miller & Carter, Nicholsons, All Bar One. They all have different menus and identities. Whereas Whitbread have opted to go in the other direction and serve the same bland rubbish everywhere.
I suspect the management haven't got any background in restaurants, but did do modules in their MBA called "the customer is always right" and "taking pride in your work is shameful"