If you are going to "judge" a book by who owns the company that publishes it instead of what it purports to teach then do you "judge" the retailers where you spend your money with the same criteria? For instance do you shop at Target, a company that is extremely liberal in its charitable donations?
Have you read the translators forward in the NIV? If so then you will understand the NIV is not a “word for word” translation and uses what are commonly referred to as the “majority text” not the textus receptus (received text).
The first English Bible was the Wycliffe Bible, followed by others including the Geneva Bible, which was the Bible of choice for those who came to America on the Mayflower. The KJV was viewed at the Bible of the Church of England and was not popular with other Protestants of that time.
Omega quoted from the 23rd Psalm, which is the 22nd Psalm in the Wycliffe Bible and reads:
PSALM 22
1 The title of the two and twentithe salm. `The salm, ether the song of Dauid. The Lord gouerneth me, and no thing schal faile to me;
2 in the place of pasture there he hath set me. He nurschide me on the watir of refreischyng;
3 he conuertide my soule. He ledde me forth on the pathis of riytfulnesse; for his name.
4 For whi thouy Y schal go in the myddis of schadewe of deeth; Y schal not drede yuels, for thou art with me. Thi yerde and thi staf; tho han coumfortid me.
5 Thou hast maad redi a boord in my siyt; ayens hem that troblen me. Thou hast maad fat myn heed with oyle; and my cuppe, `fillinge greetli, is ful cleer.
6 And thi merci schal sue me; in alle the daies of my lijf. And that Y dwelle in the hows of the Lord; in to the lengthe of daies.
http://wesley.nnu.edu/wycliffe/Psa.txt
English is a living language and words change meanings over time.
I am not a big fan of the NIV ( I prefer the NAS), however, the NIV is one of the most popular translations available today. Those portions of Scripture that are footnoted in the NIV do not appear in the oldest manuscripts or are proven additions. For instance:
1 John 5:7-8
7 For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.
8 And there are three that bear witness in earth, the spirit, and the water, and the blood: and these three agree in one.
KJV
1 John 5:7-8
7 And it is the Spirit who bears witness, because the Spirit is the truth. 8 For there are three that bear witness, the Spirit and the water and the blood; and the three are in agreement. NAS
1 John 5:7-8
7 For there are three that testify: 8 the Spirit, the water and the blood; and the three are in agreement. (from New International Version)
The Roman Catholic Church forced Erasmus to insert “the Father, the Word, and the Holy Ghost: and these three are one” into vs. 7 in the textus receptus.
In order to answer your question about the NIV you need to research the majority text and the received texts as well as the principles of translation used by the NIV translators.