Yesterday Sirlarkins asked me to expand on why people might hate the encounter reactions table in the DMG. Rather than letting this get buried in a rarely read comments chain, I'm going to put at least a few of the reasons in this post.
There are two main types of individuals who hate this thing; the storytellers and those who prefer rules light gaming.
For the storytellers, this only really effects those who didn't bother to read the last paragraph and think this roll is necessary for every encounter. I'll admit, it's a legitimate concern when people playing bards, druids, and especially paladins keep harping on the high charisma reaction modifiers and complaining that the DM is being unfair for NOT using the reaction roll to see if they can sleep with the princess. This can be especially troublesome when the DM is trying to deal with his pacing and other storytelling stuff(not exactly sure what this might be, I don't DM stories).
The rules light gamers tend to dislike the chart for 2 big reasons. First, the PHB has the +s and -s wrong in the charisma chart. Either that or the DMG has the encounter table going the wrong way, making this just one more funny thing for a DM to have to deal with in his games. In addition, there's the obvious; it's one more roll DMs(or players in some groups) have to make.
Mostly, it's important for everyone playing 2nd edition to remember that the rules are just a framework, and at least in 2nd edition, just about every rule is expendable and technically optional(says so right in the forwards).This isn't d20, removing/adding/replacing a rule will not hurt the overall system. It's also not previous editions, and nobody is going to roll over in their grave if you don't use every core rule or don't nitpick over what the almighty game designers/creators intended.