Increasingly, the errata can be summarized as:
Player's Handbook [Revision]
Player's Handbook, page 1
Remove Player's Handbook. Replace with errata.
I actually think the MM has more, its getting where almost every monsters is getting some kind of change.
Now a lot of people say, X errata over Y pages is not a lot. I disagree because its not just the number of changes, its the severity. These changes aren't delete a word here, add a line there, oh this is a clarification to that mechanic....everyone knows what it should mean, we are just making sure it says that.
Many of these changes double a monster's damage, completely change how skills are handled and how successful they are, completely change how strong a power is, etc. If the errata is "balanced", that means the unerrated version is way out of balance, which is a problem for people who don't normally pay attention to errata.
Further, remember that 4e still has to sell itself. Its still very new, and many people are unconvinced whether its better than 3e. And of course, 1st impressions are so terribly important. Its hard to sell something when you have pages of errata already out the gate.
Ultimately I'm glad to have errata, after all I would rather have fixed mechanics than continue to play with broken ones. But...people have a legitimate right to gripe everytime they see new errata with big changes continue to roll out.
Finally, we have enough errata now to the point where its time to bring back the color coding. I'm already starting to hate having to go to that bottom index and then go back up and back down again to find the new errata.