Well, there are times when I really like the cover-version of the song and I'm interested in seeing how the original sounds, and then I check out the original, just to see if it's similar.
If we take "Thank You" for example, Blackfield's version is very simplistic and scaled down, meanwhile the original is very different and has much more layers.
In this case I appreciate the original, but I really love what Blackfield did with the song for the cover.
As for not getting enough interest in checking an artist out just because of a cover, I don't know.
Sometimes I hear a cover-song that I really like, and I just feel like maybe exploring the original will let me down, and that I will loose some interest for it.
Sometimes I just don't care that much, I can hear a cover that I really like, but I feel that it's "enough", and that I don't really have a need for the original version.
It's hard to say.