Some Christians have been raising their concern too but like you said they don't want to be labeled. I think that School in Birmingham really got the Muslims out in protest because majority of the kids in that school are from Muslim families.
Look i have nothing against Gays, guest daas singh, i really don't. No one ever should feel pushed aside or singled out, BUT, what I and many others are against is when Gays or whoever else want to change Sikh Rehit and Maryada to suit YOUR lifestyle. Anand Karaj is only for a Sikh man and woman and has always only been for a Sikh man and woman. As the man of the house the Singh leads the way and the wife follows holding onto his palla. At the end of the Anand Karaj the the brides family bid her farewell and the Singh and his family take her home and they begin a new chapter in their life making Sikhi the foundation of their marriage, this is how our Gurus got married and how Sikhs got married for centuries.