I would probably say it's up to the individual and what level or protection, or more accurately what level or risk you're willing to take.
I dislocated my shoulder on my first snowboard trip, so I tend to be careful with my joints. I'm also a fitness instructor and have worked at a post-P.T. facility before, mostly rehabing shoulder and knee joints. the most common 2-splint wrist glove won't help that well if you fall hard enough. The gloves listed below tend to feel better and provide me with decent support, but realistically wrist guards are a deterrant, not a full prevention mechanism.
I also ride streetbikes now, use to dirt bike, so I have armor left over from that.
Haven't been snowboarding that long, nor am I 18 anymore, so i would say i'm more cautious. I do a lot of free-riding and more of a speed person for now, but I wanted to get into park. My park gear is as follows:
Fox Launch Suit (this is actually made for harder impact, i like it because my joints suck, and it gives a good back protector down to lower-back)
Fox Launch Suit / Upper Body Armor
Level Fly Protective Gloves
Level Fly Protective Snowboard Gloves, 2009
Demon Flex padded shorts (works well for me, doesn't ride up, cushions my backside well)
Demon Flex-Force Pro Low Padded Shorts, Men's 2009 - CLOSEOUT
Note: May be overkill to some, but personally learned from sports bike riding that its better to be a bit bulky and uncomfortable then to eat shit and break bones or loose skin.
XSportsprotective may have decent catalog of protective gear, but you can find better prices if you shop around.
Good luck, hope it helps.