I remember reading that one of its problems was that it was designed as a corporate headquarters in the early 1980s when the sort of company that might use it was both smaller in overall size than its equivalent now (i.e. it was a national and not an international company) and when that sort of company structured itself with lots of small departments that could work somewhat in isolation. And the building reflected that. It was designed too closely around the needs of a company that no longer exits. It was designed as a single entity that couldn't really be split up into general offices and let by floor. It didn't have enough large, open office space for larger business units. It was too small for large companies and too large for small companies.
Shame.
And also look at all that car parking ("three times more than current planning permission")!