A few things to consider:

1) Sorcery Advantage taken once generally gives you 2-3 powers, depending on the sorcery.

2) It almost always requires a Hero Point to use a sorcery power

3) Many sorcery powers are limited by session or scene

4) Many sorcery powers start at a Rank 1 and must be improved by purchasing the Advantage multiple times

This generally keeps them balanced in game, whereas Dueling costs a one-time 5 Points but you can generally do all the cool stuff by spending Riases as normal, and there is no need to spend additional XP later on.

John

Harliquinn hit the nail on the head. To expand, think of it this way:

To be an awesome swordsman (and just that), you are taking a 5 point advantage for Duelist, a 3 point advantage for Fencer or Bruiser, another 3 pointer for Signature Item (Weapon), 4 points for Legendary Trait, and whatever else you want to stay alive longer or take out multiple foes. Basically, to be a BEAST of a swordsman, you're looking at 15 points on the low end to truly "master" a single thing, and you'll be hard pressed to find someone who can beat you (at least until we see Grandmastery or additional advantages come out). You'll also notice that outside of the point cost, your only Hero Point expenditure is with Signature Item, and there is no limit as to how many times you can use any of these abilities.
Sure, you are focused, but again, good luck beating you at that one thing (and you can get better with magical assistance, should you go that route).

<Note: a friend and fellow GM and I tend to look at a game before we run it with out respective groups and look out for any and every potential breakable combo. His starting combat monkey was a Duelist with Fencer, Legendary Trait: Finesse, and the Glorious Virtue. Mine had Duelist with a Finesse-based Glamour. Both were equally disturbing, but not horribly game breaking.>

Sorcery, on the other hand, has a cheaper investment at the beginning but a higher end cap. 2 points is just the tip of the iceberg and gives you a few tricks (on average, two powers), and while some of these powers are rather versatile, many are one-trick ponies.

For example, Porte only really gives you the ability to know the direction your Marked item is in, Pulling a marked item to you, and being able to Walk to a major mark. It's a rather narrow focus, when you think about it, so your investment or two points gives you some useful tricks but limited scope. Adding more to this will only take you so far.
The other sorceries truly take a number of additional ranks to master. Mastering most sorceries will take about 7 purchases of the Sorcery power, meaning 14 points. Some sorceries have more versatility than others, but all come at a cost, and I don't just mean Hero Points (favors in Sanderis, Fate Lashes for Sorte, taking a Dramatic Wound for Porte, having rules to live by for Mother's Touch and Knights of Avalon, etc). 

Additionally, to master some sorceries, you are looking at quite the investment. To unlock all of the Deals in Sanderis, you only need 7 purchases of Sorcery. . .but to unlock every minor Favor, you need to purchase the advantage 15 times. For Knights of Avalon, to get 5 ranks in a Major Glamour and 2 Minor Glamours for your Major Trait, Minor Trait, and Luck would require 15 purchases of Sorcery, and would still leave you with an untouched Minor Glamour and four untouched Major Glamours. In theory, without any house rules (or adding any further ways to get additional traits), it would cost a Knight of Avalon 35 purchases to master their sorcery in their limited purview.

So really, you are paying a small amount at first, but that investment adds up to truly be both powerful and versatile (and your versatility will be based solely on the magic ability and the number of Hero Points you have). Yes, someone with 7 ranks in Sorcery (and Valiant Spirit) isn't someone to be trifled with, but neither is someone with a 5 pt Duelist Academy Advantage (not including any other perks they may have picked up).

TL;DR: 2 points isn't bad for Sorcery because you need to keep buying it to get better at magic.

Given how expensive it was to create a sorcerer character in 1e, I wonder if Mr. Wick and the other members of the design team may have wanted to go in the other direction for 2e (cheaper and more effective for starting characters.)

I think it's not an either/or. Both sorcery and duelist are almost a non-brainer from a power playing perspective.

An ussuran with duelist and 2 points on sorcery is extremely versatile because there's no other 2 point advantage giving benefits similarly useful to transforming to animals AND controlling the weather.

Duelist can also become MONSTROUS with a high weaponry skill (4 point personal story and 5 points from team stories, thus around 6 sessions maybe). 1 raise for 6 wounds? Absurd!

Glamour takes about 50 points to master. 

Each 2 points you spend gets you 1 rank in a major glamour and 2 ranks in a minor glamour.

Each Glamour Sorceror has a total of 5 major glamours they can attain (3 from Luck, 2 for their Major).  

To be honest it doesn't seem bad to me. People forget that in 1e Half-blooded sorcery was actually cheaper than becoming an apprentice duelist. The only difference was that Half-Blood sorcery could barely develop beyond that, and as such you needed to front load as a full-blooded sorcerer to progress to anything beyond simple tricks. Dueling meanwhile developed nearly as easily as sorcery but didn't require nearly as much front-loading.

To me the roles have been reversed in this edition, with dueling requiring far more front-loading than sorcery does. This is part of my reason for using house-rules for cheaper advantages that allow a character to start with a handful of manuevers. (It also helps with the duelist non-duelist combat divide, Since its easier to make room for a two-point rogue duelist advantage to represent a rougher self-made fighting technique and still be competent in a fight even though you largely focussed on being your other archetypes.)