Ah, I see. The rights of gay people, people of color, and women are "bullshit to get people worked up over petty, unimportant, feelgood crap." Let me guess: you're not gay, of color, or female. Because I assure you that to people who do fall into at least one of those categories, those are not unimportant issues! For that matter, weed, while much less important, is still a fairly big issue to many sick people who don't respond well to other medications; a not insignificant number of people. But, of course, to you, anyone who cares about weed must be a useless stoner...
You're correct to suggest that the parties are identical on a lot of important issues, which is sad, because they're quite often both on the same wrong side. But they're on different sides on a lot of other issues, which, despite your lack of interest, are actually important to a lot of people. And on those issues, it seems to me, as someone faced with chosing between them on a regular basis, that the Dems are on the correct side the overwhelming majority of the time. Not always--I judge candidates by their stands on the issues, and I have voted for Republicans in the past, and may do so again if moderate fiscal conservatives ever manage to take back the party from the religious, anti-science nutjobs that seem to be running it now--but usually.