Why is everything i-phone compatible , are manufacturers forgetting windows mobiles?

Why is everything coming out saying its i-phone compatible , are these manufacturers forgetting about windows mobiles for a reason . Dont say cause windows mobiles are crap and i-phones are far superior . That is not a valid or good response.
For these things that are i-phone compatible would a windows mobile be able to connect and they just don’t advertise this or what ?
Ok the i-phone is the latest craze , windows mobile people would love to link there phone to there hi-fi or whatever .Why don;t they make them compatible for these devices also