Of the couple dozen Alliance guilds in the stickied directory, only two make mention of Demon Hunters. One points out that they do accept Demon Hunters; they can’t just climb up the IC ranks. Another simply states “No Demon Hunters or Death Knights”, but otherwise doesn’t go into any detail.
Both of these two guilds are near the top of the list, so it’s perfectly understandable how someone, upon scrolling down the list for the first time, would see them and get the impression that this is a common restriction.
But the reality is that none of the other guilds in the directory mention such restrictions. Many guilds do indeed allow Demon Hunters (IC and OOC), and unless they state otherwise, the OP shouldn’t let those two particular guilds’ criteria sour them on their prospects with the whole bunch.
Speaking of guilds at the top of the directory list: I know for a fact that the Howling Owl is currently looking for people. They put on regular RP events that are open to the whole server. Not evil or criminal, and the guild leader is a Demon Hunter themselves! Cool people that’re totally worth checking out! They also have Horde and Alliance sister guilds.