It did exactly what Toyota wanted it to do at the time - steal market share from the Hummer H3 and Nissan Xterra without significantly cannibalizing competing Toyota vehicles like the 4Runner, and it avoided LC buyers moving down-market to a cheaper vehicle by keeping the FJC less capable:
Year FJC H3 4R X
2005 N/A 33,140 103,830 72,447
2006 56,225 54,052 103,086 62,325
2007 55,170 43,430 87,718 51,355
2008 28,668 21,373 47,878 33,579
2009 11,941 7,533 19,675 16,455
2010 14,959 3,661 46,531 20,523
2011 13,541 N/A 44,316 18,221
2012 13,655 N/A 48,753 17,222
2013 13,131 N/A 48,735 17,766
2014 11,726 N/A N/A 16,505
2015 229 N/A N/A 10,672
Marketing-wise, when the FJC was introduced, Toyota said they were trying to show what the FJ would have become if it had continued today (rather than become the 80/100/200 platform). That's evident in the front grill, which looks reminiscent of the FJ40 (and the 60, but not the 62 which had rectangular headlights), as well as the white roof, aggressive roof rack, etc. I'd counter that it does in fact look like a (rather bloated) FJ40/FJ45. In truth Toyota's "market" wasn't the FJ40 crowd but the "I want an aggressive-looking truck" crowd who liked the tougher/weirder/flamboyant (take your pick) styling of the H3, Xterra, etc.
I disagree about the 4Runner. Toyota used to offer a manual in the 4Runner (albeit I believe only in the 4cyl version) and they dropped it at the end of the 3rd gen because it didn't sell. There are a few hard core enthusiasts who'd buy a V-6 4Runner with a manual just like there are a few of us that would buy a stripped down 200-series GX in the US, but overall the market is just too small to warrant producing, distributing, and ultimately selling them. Remember, dealers buy the vehicles from the manufacturer and then re-sell them, and so most dealers want vehicles which are quick to sell, not specialty/niche vehicles which sit on the lot for months waiting for the right buyer.
Ultimately though I agree they largely sold not because of marketing segmentation but because they looked different, though I did know a guy who had a 40 who bought an FJC as his DD (so maybe a few people saw the similarities).