Healers need damage recapture in order to get more involved dps rotations

[AnotherPerson]

Before anything, take one good look at fflogs to see the difference between the average and top dps performers between all roles:

For most of the DPS, the difference is around 10%, in flat damage terms, about 1000-1200 more dps; BLM, BRD, and DNC are the main outliers, topping out at 14% and a 1400 dps difference between average and top (BRD and DNC are entirely based on party composition. BLM tops out around 1300 and a 12.7% dps difference).
For tanks, the difference is still around 10%, the flat damage difference being 600-700.

For healers however, the damage difference between the two starts at 22% for WHM going up to 27% on SCH, the numerical difference going from 1250 to 1500. In short, despite healers having minimalist dps rotations, bringing a good healer over an average one is a greater dps gain than a good dps over an average dps job.

Given that SQEX is kind of squeamish about rocking the boat, you can see how precarious the situation is regarding healer dps. Having an involved dps rotation on top of healing duties will only widen the gap between average and top healers.

Actually, having a bigger DPS rotation can reduce the numerical difference. The reason why healer DPS differences is so vast is because the best healers can minimize unnecessary healing and allow them to press Dosis / Glare / Malefic / Broil many more times than another healer can.
The reason why having more DPS buttons reduces this numerical difference is because most of the damage will no longer be made through constantly pressing your main attack skill. It could be through a burst damage skill or a long term DoT.

Having more of these skills mean you need to press your main attack skill far less for the same amount of percentage of total damage the healer can output.

1. For example, let's take sage. Sage has both Dosis and Phlegma. In 15 GCDs, if they use Phlegma II twice and Dosis III 13 times, they have a total DPS of (600 x 2) + (330 x 13) = 5490 potency.
Say they can only have 6 GCD uptime out of the 15. As long as they use their hard hitting attacks first like Phlegma II, they can get up to (600 x 2) + (330 x 4) = 2520 potency.

2. Now say Sage actually has a second DPS skill with a potency of 600 and a DoT with a potency of 700. In the same 15 GCDs, they have a total DPS of (600 x2) + (600) + (700) + (330 x 11) = 6130 potency.
Say they can only have 6 GCD uptime out of the 15. Again, they only use the hard hitting skills first. (600 x 2) + (600) + (700) + (330 x 2) = 3160 potency.

2520 / 5490 = 45.90% maximum output
3160 / 6130 = 51.54% maximum output

As you can see from the latter example, having more DPS skills in the same GCD uptime constraints will shrink the DPS variance as a result from minimizing the amount of DPS coming from the main attack button and moving the numbers around to other DPS skills that are more readily accessible and powerful. Through adding more DPS skills, the variance of the highest DPS healer and the average healer has been reduced by 6%.
If you want to go further, assuming healer total DPS is roughly the same, the amount of DPS coming from their main attack skill will be reduced further to rebalance the total amount of potency a healer can output.

2a. While keeping all the attack skills, we readjust the potency of the main attack skill down to keep total healer DPS roughly the same. Dosis will be reduced from 330 potency to 280 potency.
In the same 15 GCDs, they have a total DPS of (600 x2) + (600) + (700) + (280 x 11) = 5580 potency.
Say they can only have 6 GCD uptime out of the 15. Again, they only use the hard hitting skills first. (600 x 2) + (600) + (700) + (280x 2) = 3060 potency.

3060 / 5580 = 54.84% maximum output.

Now the variance has been reduced by another 3%. This reduces the total DPS variance by 9%.