what?

Found out yesterday that the new hires in our team will be one grade lower than me. Their titles will have the word Senior in it. We are talking about someone with 1 year experience vs 7 to 10 years or more. This ticks me off. I understand these new hires are top in the class, and are really smart etc. etc. Does that equal experience? I understand they should be compensated better than the average graduates, but how can there be such a jump? If they are getting the senior title, then they'd better do the senior job.