Do you have to face Yerushalayim?

The gemara in Brachos on daf 30a says that if you are in chutz laaretz then you should face Eretz Yisrael when davening Shmone esrei and if you're in Eretz Yisrael then you should face Yerushalayim and if you're in Yerushalayim then you should face the bais hamikdash and if you're in the bais hamikdash then you should face the Kodshei Kodshim and if you're in there then you should face the bais hakapores. What happens if you're in Irbid, Jordan (see this map) which is east of Israel but is actually northeast of Yerushalayim. From this gemara it sounds like you only have to face west so you're facing Eretz Yisrael. From the conclusion of the gemara it sounds like you should face Yerushalayim anyway because it concludes that everyone faces the same place. Rabeinu Yonah says this explicitly that everyone should really face the bais hakapores. My question then is why doesn't the gemara just say that? Why does the gemara give different things depending where you are? Just say that everyone should face the bais hakapores in the Beis Hamikdash!