Tasteless as the ad may be, the LGBT community should just take it on the chin and ignore it, not start throwing around accusations of 'transphobia'. It's a fact that you will be offended at some point in life, and the sooner you accept that you don't have a right to not be offended the sooner you can grow up and get on with life.
End note: Good to see the company behind the ad stood up for themselves, rather than pulling the ad and apologising pathetically as every company seems to nowadays when some hysteric wails 'racist/homophobe/transphobe, etc'.