Thomas' 500th home run seemed to comment on his career as a whole, coming as it did in a loss (8-5 to the Twins) and coming in a game in which he was later ejected. This is not to call Thomas a loser -- far from it -- but I have always had a vague feeling of incompleteness or disharmony when thinking about his career, underscored by the bad or injured seasons that tended to interrupt the flow of dominant ones. The fact that injuries rendered him a non-factor during his club's championship season. These factors, combined with him playing DH as opposed to some glamor position have caused many to underrate his accomplishments, which in turn renders his 500th home run somewhat less magical than other players'.
Biggio's 3000th hit likewise came laden with meaning. From MLB.com:
He singles to right for No. 3,000, tying the late Roberto Clemente on the all-time list and securing his Cooperstown future. Then he tries to leg it into a double, is thrown out to end the inning and sees teammate Brad Ausmus rush to him as a celebration scene begins.
Being gunned down while attempting to squeeze out a little something extra describes much of the past several years of Biggio's career. Biggio hasn't been an elite player for many years, and ceased being even an average one two or three seasons ago. His quest for the glory of 3000 hits, while understandable, has cost his team much recently, as the Astros have forgone a desperately needed rebuilding effort in the name of keeping their biggest name happy. Has Biggio demanded this? Not that I know of, but the effect has been the same as if he had.
I have great admiration for both Thomas and Biggio, and I consider each of them to be among the best to ever play the game. But their milestones are bittersweet ones, each carrying a reminder of some of life's more troubling aspects. No matter how important you are, you're not indispensable. No matter how skilled you are, there are no guarantees that you will always be appreciated. Even the most loved among us will one day wear out their welcome and become a burden. Yet we all hang on anyway, because really, what else is there to do?