Light armor

[Charlemagne]

Is there a good reason to prefer light armor over heavy? Mages shun armor because it affects their spells, but light affects them as much as heavy, so if they are going to use armor it might as well be heavy. You need to avoid heavy boots if you want to sneak, but all you need to do given the need is remove the boots, or wear light shoes (and the rest of your outfit can be heavy armor). Furthermore, as you advance in sneak, heavy boots stop being a problem.
So I'm planning to play as a rogue and I planned to use light armor to be in character, but then I asked myself, what's the point?
Futhermore, light armor is pretty disappointing. One would think that mithril or elven would be very protective, did you see Frodo in LOTR, but no.

[Tisiphone Edge]

The master perk of light armor increases the protection rating of light armor by 50%, putting it on par with heavy armor but with less encumbrance. On the other hand, the master perk of Heavy armor gets rid of the encumbrance that comes from wearing it. So in the end, it doesn't really matter once you are a master in either.

[JakGrant]

I could be wrong, but 1) I'm pretty sure there is a speed factor difference between the types, though this could be negated through master level; 2) the weight of the armour is always going to be a factor, unless you're a melee rogue, you aren't going to run around in heavy armour, because you simply won't have the strength to carry it all; 3) as for mages, i'm pretty sure they have less of a penalty with light then heavy armour; 4) LotR ? you can't really compare, not every "D&D" based system is the same. Most are dsiegned in different worlds and therefore the systems are different; and 5) traditionally rogues wear light or medium armour only, never ever heavy. Some might disagree, but course like point 4, Elder Scrolls is their own system, but it still uses the base of some of the more traditional and first D&D and AD&D.

Finally, if none of these are valid arguments, I would simply say:
a) if you're a ranged rogue who uses stealth, wear light armour; or
b) if you're a ranged rogue who doesn't use stealth, wear light armour; or
c) if you're a melee rogue who uses stealth, wear light or heavy armour; or
d) if you're a melee rogue who doesn't use stealth, wear heavy armour.

In summary:
if it's a) or b) then you should never be using heavy, simple because heavy despite being governed by the endurance stat, which should be one of 3 of a ranged rogues favoured stats of: end, agility and speed, NOT str, that's at least 4th; or
if it's c) your favoured stats are going to be str, end and speed most likely, and therefore you have the carrying capacity from the get go of carrying heavy armour, which a and b setups do not give you; or
if it's d) no offense meant, but if you're melee and not using stealth, you should be going combat and a fighter setup not a rogue, it's kind of self defeatist, but your favoured stats are still going to be of point c.