From the late 1980's to early 2000's, baseball was plagued by the steroid era, a time of massive sluggers, shattered records, and immense scandal. As such, it is very difficult to properly judge players from that era, and most people struggle to form concise opinions on specific candidates. I think it is a mistake to take players from this era solely due to performance, since for many that performance was enhanced through artificial means (which is not only cheating, but also a false sense of a player's ability), and on the other hand, it is a slippery slope to play the detective and try to determine for oneself who was innocent and who was guilty. For those who look more critically than that, but still not critically enough, there are two principal errors that many people fall into.
The first error is committed by those who simply discredit the entire era as tainted. They either assume that everyone who played during that time was taking steroids and is thus undeserving, or merely deplore the entire time period and opine that the period itself does not deserve to be represented by the Hall (which is a subtle way of shying away from evaluating candidates because the waters are too murky). Tony Gwynn, a clean player who won batting championships throughout the steroid era, used to complain that his accomplishments fairly achieved were devalued because of the time in which he played.
The second error is to discount certain batters' achievements as products of an excessively offense-laden era, such as the 1930's. They were not truly great, some argue, but were carried by the time in which they played. In my opinion, this argument makes no sense. The primary reason for the boom in offense was because players were taking steroids, contributing to home run totals unheard of in baseball history, making it harder for clean batters to compete with them for accolades and recognition (not to mention league-adjusted stats). While steroid use was evidently more of a problem on the hitting side, many pitchers were juiced as well, presenting an additional challenge for hitters who refused to jab themselves. Therefore, the statistics of clean players from this era should not be devalued, but actually valued higher.
Two candidates previously advocated for on this blog who are relevant in this discussion are Moises Alou and Carlos Delgado. Moises Alou had a fine career (.303 / .369 / .516, 332 homers) but doesn't appear to be a Hall of Famer on the surface. However, his career statistics could have been better if he never faced a tainted pitcher, and his 128 OPS+ could have been 20 or more points higher if not for the other batters he had to compete with. All in all, if Alou had played in an era untouched by steroid use, then he would likely be a borderline Hall of Famer.
Delgado, on the other hand, is at least a borderline Hall of Fame candidate as it is (.280 / .383 / .546, 473 homers), but has yet been shown little interest by the Hall, most likely because he seldom beat out the steroid users for league leadership in offense. If not for rampant steroid use during his career, he likely would have 500 home runs, and his 138 OPS+ might have been closer to 150 or 160. In a perfect world, if he had achieved these figures, there would be little discussion about his worthiness of induction.
