For me I had several reasons:
1. I like how the NKJV includes “added” English words in italics, that can be very informative in prepping for family worship or a SS lesson, so I don’t dogmaicaly emphasize an English word that was added for sentence flow and was not even in the manuscripts.
2. I like the KJV language; however the hard truth is that the KJV form of English is not what we speak today. Sure we can try and learn it, but the reality is that old English really does need to be updated. I feel the NKJV updates the English but keeps some (not all) of the beauty of the language used in the KJV (I know some disagree).
3. Family Worship: So for family worship (wife, 5yr old, and 2 yr old), I find I like the NKJV being based on the TR (I am not settled as a TR guy and still respect CT), but with an updated English for an easier read and comprehension for the whole family. So far we have found the NKJV reads just as smooth if not smoother in many areas compared to ESV.
4. In researching (on a layman level), it seems the NKJV would be the 2nd choice, if you were to really press a hardline KJV proponent. I am NOT a KJV is the best kinda guy (at least not today). However I have been finding that the NKJV strikes a remarkably solid balance between camps in the whole TR, MT, CT discussion. The NKJV seems to be a good

compromise

because it is based on the TR, but at the same time it will footnote the text variants from CT, which at least will give me pause and remind me to look more into certain passages. The textual variants footnotes drives that for me. The ESV leaves many footnotes out and even some verses, that as the reader I would at least like to have the option to consider certain verses or word choices.... instead of not even being made aware that there could be a possible different reading. That said, I am not even sure a 1611 KJV would have textual variants footnotes (I could be wrong on this). After all I am not well versed in Hebrew or Greek so I really do like the footnotes. My understanding is that the NKJV preaching bible has the Full amount of variant footnotes, which I like for private bible study.