Let's say you were light armor or medium armor and wanted to train heavy? Well it's easier to do this from 1-50. You're actually penalized when you get VR1 and you are able to train things less faster. Isn't that kinda nonsensical? Sure I don't mind the slower xp, but training is training. If you're a veteran you're likely to learn skills faster.
These players that have just bought the game and leveled through the 1-50 content on a weak build probably have to go through hell just to change to a viable build once they finally talk to people or read enough to know what they should be doing.
Imagine how long it'd take to learn a new weapon type, armor type, skill line from 1 or 5. You'd be grinding for a week in Cold Harbour's public dungeon and even then you'd probably wouldn't max it. Hell, you're better off just using a spec that will get you through quests and just changing to whatever you wanna train when you turn stuff in. But even that takes a while. I think Bow from 48 to 50 took like 30 quest completions a piece if not more.
And besides, it's not like you'd be a master of all trades or as if knowing all these skills would make you super powerful. You're still either a Dragonknight, Sorceror, Nightblade, or Templar. So if you're like most and try the other classes out you gotta start all over and learn all those too.
Could you imagine trying to learn all the skills on all 4 classes on one account? That would take a casual at least a year. Yet leveling is and can be super fast if you know what you're doing. /shrug... maybe if it were more fun to grind but it isn't. I'd rather grind skills like 1999 EQ where you'd get skill ups very slow. At least you could just go out and train on easier enemies. It always took a while, but you could know a skill or two out in a day. Easy. Hell, I macro'd begging in a SoF zone's tower so it'd beg from this human npc and got 400 nearly overnight. And begging took FOREVER.