However, the primary pet class' utility was lacking in comparison,
That is what I hate the most about you mages. For some reason you think you're the "kings" of the pet world. No one has ever explained why that should be the case in a reasonable manner to me before and I totally disagree with that attitude.
To break it down for you in the most logical manner possible. A long long time ago, before the Beastlord class was even a twinkle in Sony's eye, there was the mage class....
I apologize for the massive snipping of your post, but I just wanted to point out that referring to the time before beastlords existed as a means of establishing where mages and beastlords should stand currently isn't even remotely logical, much less "the most logical manner possible." It's like arguing that reptiles should be considered the most advanced creatures on earth because that's what they were before mammals existed, or that the Tampa Bay Buccaneers shouldn't have won Super Bowl XXXVII because they didn't exist back when Green Bay won the first one.
Moreover, your approach in your post (in the parts that I haven't quoted) isn't even logically consistent. According to you, the strength of mage pets was a byproduct of their reduced desirability in other areas and a logical extension of their "summoning" abilities, as opposed to a "vision" of mages as the ultimate pet using class. In other words, you're telling a story where mage pets were something of an afterthought to prove the point that the primary design of mages was to be the ultimate, unsurpassed pet class for all eternity.
The real answer is that mage pets and beastlord pets (and the abilities each class has to deal with pets) have to be viewed differently because of the fundamentally different ways in which they are used. Mages don't get fast, super-efficient, high powered heals because if they did, they could use their pets to tank much more effectively than they do now, which apparently SOE doesn't want (or at least hasn't wanted in the past). Mages don't get slow for various reasons, but one thing that really stands out is that slow actually does not complement some of the other mage primary abilities, like damage shields. If a mage pet is tanking something, the mage wouldn't even WANT it to be slowed so long as the pet can survive the target's damage output. The faster a mob hits, the more damage your damage shield does. Again, this is why mages covet fast, powerful heals (along with tough tanking pets) -- it would allow them to get the most use out of damage shields while also increasing pet survivability. And because mages can do almost all of their damage from range, their pets are able to tank for them.
Beastlord pets work differently (in fact, beastlords themselves play almost entirely differently as a melee/hybrid than mages do as spellcasters, which makes these comparisons all the more ridiculous). Beastlords can't use thier pets to tank for them, since for the most part beastlords need to be in melee range to do damage, which prevents the pet from taking aggro from a mob because of the hard-coded mob target preferences. By and large, beastlords care more about the damage output of their pets rather than outright tanking ability.
In a world where we were starting from scratch, we might imagine mages having powerful tank pets to defend them, and beastlords having high damage pets to assist with dps, based on how each class actually uses their pets to complement "weaker" areas where they need help. Each pet would actually have different strengths that complemented the class that it belonged to, and if one pet surpassed another in a particular area or possessed abilities that weren't shared by the other pets, it wouldn't be viewed as some kind of MMORPG treason.
But we don't live in that world. We instead live in a world where people (or at least mages) imagine mages having pets that are the best at everything, by a large margin, in every conceivable situation, simply because they existed first. It's not a world that makes a whole lot of sense, though. It's the primary reason these discussions never go anywhere.
