When arguing that burst doesn't need a fix, missiles are the logical example to make. They are easily the most balanced example of burst in the game. The drawbacks and damage loss are well-balanced with the advantages in defeating fighter screens and point-defense, especially because the loss of accuracy is meaningless to missiles.
Unfortunately, with many weapons, there are 'correct' and 'incorrect' choices. As you say, Fleet Admiral, there are many situations in which weapon upgrades have to be carefully weighed and balanced, and this is good. On the other side of the coin, there are other weapon upgrades where your choices are obvious - some upgrades are ineffectual, and others are too effective.
Projectile cannons and energy cannons are a good example, where burst doesn't increase DPS, while the loss of accuracy and range far outweigh the 'shotgun' effect.
When designing a game, it's my opinion that all choices should strive to be strategic choices. That is, you should be weighing advantages and disadvantages, in this case, when choosing what to upgrade. There should never be an 'incorrect' upgrade, or a 'correct upgrade. You should never have a 'best' or 'worst' choice.
