Prior to the appointment of Ruth Hunt as CEO of Stonewall in February 2014, Stonewall was an LGB charity. Not LGB, LGBT.
During the FY 2014, during which Stonewall introduced 'T', their income grew 24% (previous years growth were only around 5%). Stonewall's income grew from £4.3m between 2014 and 2016. Executive staff benefits increased from £204k to £312k between 2015 and 2017.
As part of 'going trans', one of Ruth Hunt's first acts was to embrace Aimee Challenor, whom she appointed to Stonewall's new trans advisory panel: twitter.com/stonewalluk/status/497291683550474242
As a charity functioning as a income-generating business, Stonewall needs to grow its revenue, and increasing the size and scope of 'transgender' will allow it to continue to increase its income and pay more executive benefits.
Sticking with its original LGB brief saw income stagnate, but by going T, Stonewall has received millions of pounds in extra cash.