Really, you felt compelled to do this?
The purpose of Ash Wednesday is to remind us that we are all going to eventually die, in preparation of engaging in a somber atmosphere to start Lent (leading to Easter and the resurrection of Christ). It is a universal thing, so everyone from infant to the elderly, gay or straight, all get ashes (if you are Catholic or a Christian tradition that follows this).
Engaging in identity politics takes away from that. So I completely disagree with this sentiment. Not because I want to exclude gay Christians from Lent, but because this is a day all people. You show solidarity with people by treating them with respect through the year, not putting glitter on your forehead. Because this whole glitter thing is a distraction from what this day is about.
Gays already have Carnival/Marid Gras to engage in identity issues. And Judy Garland's birthday. And the Folsom Street Fair.
Bonfire of the Vanities: Sin Turns Us From God, Confession Turns Us Back