I agree that the Hall of Fame is a semi-irrational institution, and we all have our share of quarrels with individual borderline cases that were left out for no apparent reason, or elected based on fan and teammate campaigning more than actual talent.  (Ask me about Gil Hodges versus the Yankees of the 1950s sometime.)  And for my money, Bill James's book on the subject (Politics of Glory, or whatever it's unmemorably titled) is still the classic work on this question.

This is just my opinion, and there can be reasonable arguments on both sides, but I kind of hope that the HOF bar is set very high for the pure sluggers of the 1990s era.  The counting stats just should not count much for these guys.  In my knee-jerk opinion, Sosa, Palmeiro, and their ilk don't really quite belong in the Hall, or else the door is open for a lot of other hitters.  There's no strong argument, at least, for many of the home-run accumulators of the 1990s, that they were ever the dominant hitter, immeasurably more feared than those around them.  Instead, they were good hitters with unprecedented power in an era of very diluted pitching.