Are we talking about brewing companies like Sierra Nevada? Or are we talking about beer names like Sierra Nevada Pale Ale?
For brewing companies, I think that the majority still have classic names. Many companies like Dogfish Head, New Glarus, Bells, etc. have breweries named after their location or the founder's last name. Others like Stone, Rogue, and the like are slightly more creative, but still pretty basic IMO. There are a few strange ones out there, but they are definitely in the minority.
As far as individual beer names go, I think that has to do with the growing number of breweries. When Sierra Nevada made their pale ale, it was one of the only pale ales produced in the country, so they needed little more than their own brewery name and the style to separate them from other beers that were available. With the number of pale ales available, whether or not some individuals think they may be immune to marketing, the truth is that for the average person who is facing a wall of pale ales, if one has an interesting name and interesting bottle art, and the rest are just plain white boxes that say "PALE ALE" in block letters on the side, guess which one gets bought?
So in short, as much as people don't like to associate it with craft beer, it's all marketing.
Also, I re-read the OP and this is slightly off topic because the OP was asking for history, but I wrote it all already so too bad.
