I am a practising Catholic, (heaven knows I need the practice!), and a confirmed heterosexual, but even I can see the irony in an old celibate man, in a white frock and a hat like that warning against the influence of "the gay lobby"!
My opinion, for what it is worth, is that Pope Francis tried to acknowledge, and find a place for, gay people within the Church, acknowledging and believing that they were amongst Gods children, and should not be turned away. It is perhaps fair to suggest that Cardinal Gerhard Ludwig Müller does not view the gay community as charitably; cynically I doubt he views any views other than his own very charitably.
I doubt that Pope Francis came to that stance without much thought and prayer; his formation was after all as a Jesuit, and The Society of Jesus is known for intellectual rigour and orthodoxy. Mind you, it is also worth bearing in mind that you can never be absolutely certain what the SJ is going to do next!
Perhaps he (Pope Francis) was also mindful that he wanted to avoid the mess which the Church of England (or rather the worldwide Anglican Communion) finds itself in, various factions fighting to decide whether they want the next Archbishop of Canterbury to be male or female, gay or straight, celibate or at it like rabbits on Viagra!