Just check his basic career stats:

Batting average: .285
Home runs: 185
Hits: 2,365
RBI: 1,003

He was an above average shortstop who partnered with an above average second baseman to make one of the best duos in baseball history. But, sorry, being in a duo does not get you into the HoF. Period. It is about individual accomplishments.
Yes, he has some, like 4 gold gloves, 3 Silver Slugger awards, he won comeback player of the year in '83, and he won World Series MVP in '84.

4 Gold Gloves in in that period of baseball is pretty nice. They didn't used to just hand them out like candy like they do now. Three Silver Slugger awards are nice too but let's face it. that is where his real accomplishments stop. He won MVP of the World Series on a Tigers team that was unstoppable; half a dozen players could have won the award that World Series. And Comeback Player of the Year do3sn't mean shit.

In truth, Trammel didn't come close to meeting any of the categories that are vital. He didn't hit .300 or better lifetime. He didn't hit 200 home runs let alone 400 or 500, and he didn't come close to 3,000 hits.

Let's look at Cal Ripken Jr. He only hit .272 lifetime but he has 3,184 hits, 431 HR, and 1,695 RBI, 2 Gold Gloves, 8 Silver Sluggers, 2 AL MVP, 19 All Star Appearances, Rookie of the Year, 1992 Roberto Clemente Award, 1992 Lou Gehrig Memorial Award, 1991 Home Run Derby winner, and other records like the "straight=appearances" record, etc.

But hey, maybe comparing him to the greatest shortstop of all time isn't fair? Let's look at another HoF SS.

Robin Yount
Average: .285
Hits: 3,142
HR: 251
RBI: 1,406
He also had 3× All-Star selection, 1 Gold Glove Award, 3 Silver Sluggers, and was AL MVP twice.

So, he had the same lifetime average as Tram, he was in the 3,000 hits club, and had over 200 HR (two categories Tram never came close to), just as man Silver Sluggers, and Yount was actually AL MVP twice (something Trammel never did). Realistically, Yount is in because of the 3,000 hits (in my opinion). Still, the 3,000 hits are what pushed him over.

Still, Trammel, while having some nice accomplishments and being in the upper half of shortstops while he played, simply has not done enough to be a Hall of Famer. The baseball HoF is notoriously strict. Good, I don't want it to become a joke like the other sports. That said, Trammel was my favorite player growing up, I love the guy, but he is simply not a Hall of Famer. You can compare him to numerous other HoF shortstops and you will see he lacks the numbers. He is not a Hall of Famer.

BTW, in case you wonder, I think Dawson is suspect, Blyleven probably deserves to be in, and Alomar (whose numbers shit all over Tram's) deserves to be in.