I am a stealth archer. Stealth is not a template it is a skill that anyone can learn if they so choose to invest the time and skill points to it. Stealth isn't used alot on other shards but a good 30-40% use it on Siege and for good reason. Stealth is often the only way to go anywhere on siege due to all the pvping around towns and roads especially if you can't gate ie no magery on your character. Now note there is actually a way to defeat Stealth and its easy to use. Its called the Detect Hidden skill. Now, that also requires you to allocate skill points to it. So, I recommend you do as I do. Either put your time in and get a soul stone once a year, or buy them. That way you can get around the skill cap issue. One costs you time and one costs you money so choose one.
You must be new.
Let me explain this to you. Here is what happened.
Production shards were overrun by stealth archers. People on production shards complained and complained and complained, eventually EA responded.
EA's "fix" was to install passive reveal on production shards. At the same time, they increased the delay on the use of the detect hidden skill.
On Siege, we didn't get passive reveal but we are saddled with the increased use timer on detect.
The effect of this has been to create a shard full of stealthers.
Now, with that many stealthers, why don't more people pick up detect hidden as you have suggested?
Let me explain that to you. The simple answer is that detect hidden doesn't work well enough.
I have a character with gm detect. This gives me about a 50/50 chance to reveal someone with gm hide. Sometimes, I fail 3 or 4 times in a row.
Think about this for a second. A stealther can hide just as often as I can reveal them, but hide never fails while detect only works half the time at best.
In other words, hiders can hide every 7 or 8 seconds while detecters can only reveal them on average every 14-16 seconds.
GM detect will never be effective against gm hide because it simply doesn't work often enough.
This could be fixed by reducing the skill use timer on detect hidden. After all, it was changed on Siege as a balance to passive detect and we never got passive detect.
Alternatively, change the percentage chance for a detector to actually reveal a hider. 50/50 at 7-8 seconds between uses is simply not good enough.
I don't mind if you want to use stealth to sneak around, but if someone does invest 100 points in detect hidden, as you suggested, it ought to actually enable them to consistently reveal hiders and currently it does not.