Yep, wear more protection. Durango, this topic elicits more varied input than you can shake a stick at...or get beaten with that same stick. Some bicyclists are some of the most resistant folks I've ever come across to wearing protective gear. Some have a "wuss" factor attached to it, some have a social disdain for it, and there are many other reasons. Please note that I say "some bicyclists"...but the ratio seems higher among bicyclists than a lot of other physically active sports that have the potential for injury.
I understand what rkj was getting at with the statement, "How often you fall depends on the risks you take", but it's hard to calculate. You can fall any place, at any time, on some of the most mundane sections of trail. Granted, the more risks you take in technical terrain, the better the chances, but off roading always has this risk to some degree.
I'm not a real freerider, though I will get some decent air on jumps and drops occasionally, but most of the places we ride have some decent rocks and technical areas. I always wear some very comfortable and breathable knee/shin guards. You ride with them for just awhile, and you don't even know they're there anymore. I also wear a modified DH helmet for most aggressive trail use. It's very breathable and as good an air flow as my old Giro Switchblade. I wear full finger gloves all the time. I also wear long sleeve CoolMax jerseys all the time...for sun as well as abrasion protection.
On some trails in Moab and a major trail complex near my home, I even wear a light breathable MX-style body armor set complete with elbow/forearm protection.
Do some other riders think that I, and some of my friends, wear too much protection?...yes, often. Am I the one, either on the trail or at the end of the ride, swabbing up blood or bandaging gashes?...not usually...and if I am cleaning up a wound, the unprotected rider would have probably been cleaning up worse. Going to Moab often puts things in perspective, because you get to see a ton of riders of all kinds out there. I don't know how many bare knees and shins I've seen gashed open. I've seen broken teeth, busted/broken noses, split chins, ears nearly ripped off, etc., etc. I've crashed in some of those same places and just got up, dusted myself off, and went on my way.
Does armor stop all injuries?...of course not. Will it stop or minimize many serious and debilitating injuries...most definitely. So...you have to ask yourself...how much armor am I willing to wear? Am I willing to put up with the disdain that sometimes comes from "some" other riders for wearing armor? This is always an interesting topic that draws a myriad of responses. People don't have to wear armor of any kind when they ride, and I'd never even suggest the requirement of such...but to some degree it can be a wise choice.