Skepticism for Term Limits

I've always been rather skeptical of the idea of federal Congressional term limits, for various reasons. The Monday edition of Roll Call, with a complete listing of seniority in both chambers of Congress, seems to provide supporting evidence. It is true that some people have been in Congress practically forever:
Date is beginning of service in the chamber.
Senate:
1. Byrd (D-WV) 1959
2. Kennedy (D-MA) 1962
3. Inouye (D-HI) 1963
4. Stevens (R-AK) 1968
5. Domenici (R-NM) 1973
House:
1. Dingell (D-MI) 1955
2. Conyers (D-MI) 1965
3. Obey (D-WI) 1969
4. Rangel (D-NY) 1971
5. Young (R-FL) 1971

However, skipping down to the middle of the lists is interesting.
Senate:
49. Santorum (R-PA) 1995
50. Frist (R-TN) 1995
51. Wyden (D-OR) 1996
House:
217. Brady (R-TX) 1997
218. Cannon (R-UT) 1997
219. Carson (D-IN) 1997

The Majority Leader in the Senate has been serving for barely over a decade, and over half the Senate has been in office that long or less. In the House, over half of the chamber has been replaced in the last 8 years or so. Only 114 Represenatives were elected before Clinton's first election, and only 76 before Bush I's. Only 24 were elected before Reagan's first election. Turnover may not be as high as some people would like, but is seems plenty high as it is.