It was only dragged into zone 1 in order to charge higher fares to recoup some of the cost of building the Northern Line extension. If it weren't for that, it'd be zone 2 - and one of the less well-connected bits of zone 2, at that.
I don't have that much of a problem with it, tbh - before the development it was a weird light industrial bubble, disconnected from the rest of the city. Now it's a weird bland commercial bubble, disconnected from the rest of the city.
And we've lost Marco Polo House, the home of QVC, and gained Apple. Seems about a wash in terms of cultural value as well.