That's ridiculous. Mine have always worn evenly, despite all the scuttlebutt about RH bends etc. At around $500 for a pair, I'd be going broke if mine only gave me those kms. I expect 25,000. I'm not careful about acceleration, regularly carry a heavy pillion and run 42/42.
Now that's on an ST1300. I have run PR2s, 3s and 4s, all with similar results.
When I had an ST1100, I got 11780 from Bridgestone 021s. I sold it with a pair of Metzeller Z6 hoops that had 5683 km on them and passed the Roadworthy easily, implying they had another 5000 or so left in them.