I think it is rather clear if one listens to enough Japanese songs that "夢" is used all the time; it is in many corporate messages as well from the commercials I recall. As a song example, I am currently studying 心臓 by TOOBOE, and this line is the first:
The song and music video clearly present a false idea of love by the narrator, but why "dream" here? I assume "dream" here refers to the idea of what their relationship will become of (thus "dream" is synonymous with "ideal" or "outcome"), and how the partner seeks to know what the other will do next, but is this to assume that no other word can convey this concept?
つまり, when the word "夢" is said, is the idea of "outcome/future" the right synonym?
EDIT: "夢" is "dream," yes, but that does not explain why it is used all the time when it comes to relationships and slogan-ing.