My 4Runner is mostly stock too. Why? Many reasons:
1. Over the years I have built many many off road vehicles and spent tons of money and time on them. For what? Sure, I could say better capability and performance right? Sorry. What I gain in off road ability I have to give up somewhere else and usually that is in on road ability and reliability and if you were honest you would say the same thing too. I am with [MENTION=118321]Jetboy[/MENTION] in saying for $5K you can build a vehicle that will run circles around the 4Runner on a trail.
2. Let's face it... most build their vehicles for 90% looks and 10% capability. Some of you guys reading this are going for a "look" that defines who you are, much like wearing a "Nike" shirt to show you are athletic. You fix up your vehicle to show you are "rugged" and "outdoorsy." There's nothing wrong with it (as long as you admit it) but I am way too old to play into that crap anymore. I really don't care what people think. With that said the 4Runner, in my mind at least, looks great right out of the box.
3. I drive 99% of my 25K/yr miles on the HIGHWAY. That is 24,750 miles on the highway and 250 miles off highway. With that said that's probably more miles off highway a year than 90% of those reading this! I am a realist which is why I bought my 4Runner. In stock form it does great on the highway and for those 250 miles a year it does great off road. I could probably get by with a Highlander or a RAV-4 but for work I need a vehicle that can have a steel cable attached to it and be dragged through the mud by a log skidder or a dozer. Sort of need a frame for that lol.
4. The 4Runner is stock form will go places even I am not willing to take it. It is not a beater trail rig with a full roll cage and I don't treat it like that. If you do then great because that means you have much more money than I do.
5. Reliability and durability of a stock versus a modded vehicle. Mine is a daily driver and it needs to be reliable.
Lastly, vent shades, tires, running boards and floor mats are not mods. When you go to a double shock setup or weld in a new crossmember or design a swaybar disconnect (@wfo9) then you are modding. If you have to cut, beat or otherwise change the shape of your vehicle then you are modding.