While watching a movie in the theatres, the entire atmosphere changes when you start viewing scenes which are shot abroad. This is one reason why many big budget flicks tend to choose foreign locations not just for song shootings but even for the talkie part. But here is an underlying truth.
According to the filmnagar seniors, shooting in foreign locations is more like an encouragement to hero, heroine and key members of the unit. It cheers them up in a positive way. Earlier, songs in foreign locations were helpful because distributors gave more money to buy the movie.
But now that situation is not there. Of course some amount of rich appeal will be there and an international location gives some branding. Hence, some ordinary heroes who are yet to make their mark have their songs canned in Bangkok or Dubai. Otherwise, this process is just for motivation.