The issue with "the math" is in the variety, not the math itself. Take the good old 18 (or even 20) post-racial primary ability score with the +3 proficiency weapon vs. the 16 with the +2 as a simple example. In a campaign, weapon "upgrades" don't usually happen at the same time in a lot of games. If the +3 user gets his "upgrade" sooner, then he's at a +3 for a time. Sure, there are trade-offs as there's definite benefits from allocating points in to other abilities, but not all classes need a lot of tertiary stats also. Certain backgrounds made it so you don't have to put a lot of points in to Constitution to be a functional defender, for example, but an increased number of surges is still very helpful.
With Expertise, that 16/+2 character is on even footing with the 18/+3 at paragon so long as they spend the feat. Without it, the 16/+2 character may feel they're falling behind at the start of the new tier when foe's abilities go up. Expertise gives them a chance to be on even footing. It beats either becoming unhappy with a character and "killing it off" after 10 levels for a new one.
This then opens up a conundrum of tied powers to ability scores and different proficiency bonuses but that's not really the focus of this thread. The "best" alternative would not have been in any way simple or efficient: a wall of pre-requisite text. I mean can you imagine what that would look like?
Heavy Blade Expertise
Prerequisite: Must be wielding a heavy blade with an initial post-racial primary ability score of less than 18 and/or use of a weapon with a proficiency bonus of less than +3. etc. etc.
How cumbersome is that? It was better off just leaving it with less text and letting those accuracy optimizers have their toy too.
There are two feats I generally find closer to "must take" for a character: Toughness for a low-level defender (or potentially Durable) and Speed Loader for a non-striker crossbow user.
With Expertise, that 16/+2 character is on even footing with the 18/+3 at paragon so long as they spend the feat. Without it, the 16/+2 character may feel they're falling behind at the start of the new tier when foe's abilities go up. Expertise gives them a chance to be on even footing. It beats either becoming unhappy with a character and "killing it off" after 10 levels for a new one.
This then opens up a conundrum of tied powers to ability scores and different proficiency bonuses but that's not really the focus of this thread. The "best" alternative would not have been in any way simple or efficient: a wall of pre-requisite text. I mean can you imagine what that would look like?
Heavy Blade Expertise
Prerequisite: Must be wielding a heavy blade with an initial post-racial primary ability score of less than 18 and/or use of a weapon with a proficiency bonus of less than +3. etc. etc.
How cumbersome is that? It was better off just leaving it with less text and letting those accuracy optimizers have their toy too.
There are two feats I generally find closer to "must take" for a character: Toughness for a low-level defender (or potentially Durable) and Speed Loader for a non-striker crossbow user.