I think the people who in reality were most affected where those who actually used the 1984 NIV consistently as their main bible - who grew up using it - who memorized verses using it - etc. As people whose faith was most impacted by that version, they probably felt the biggest impact (or feared the biggest impact) by a change. Happens all the time. That's the only reason we have so many KJV-fanatics out there - because they're upset that other versions don't align with what they've grown to know and love as the Bible.
It's all one big pity party IMO. The NIV was never a very good translation (and the KJV is absymal). What the NIV has going for it is how easy it is to read in English and the fact that it is a brand-new translation instead of being based on earlier versions, which allows it to incorporate newer scholarship than a lot of modern versions. And while it may not always come up with a very good rendering, it is sometimes ahead of the game.
For example, in Isaiah 12:2, the strange phrase appears "because my strength and song is Yah YHWH." It wasn't until the last 50 years that scholars realized, based on Ugaritic and other ancient Semitic languages, that the word "song" isn't really the word "song," but is an ancient word meaning "strength" or "might." It's kind of technical, but basically what happened is, over time, two sounds that were similar, fell together in graphic representation. In other words, if you wanted to represent the two similar sounds, you used the same consonant. The problem is that the word "song" is based on the one sound and the word "might" is based on the other sound, with no way to distinguish between them when writing. You have to use context. So scholars realized that this was happening in Isaiah 12:2 - that even though it looked like the word "song," it actually represented the word "might." This was a new realization about the way the language was functioning and it still hasn't made its way into most translations--except for the NET Bible (gives me strength and protects me) and NIV (my strength and my defense). Clearly, the NIV is better than the NET Bible in this rendering, but both of these brand-new translations have learned a few things from advances in scholarship that most other modern translations have not. Almost all translations are stuck with the silliness that YHWH is one's "strength and song."