Not sure why you called on me, but sure, I'll give my two cents.
Personally, I'm fine with the lack of aging in the way we think of it, due to the huge time scale involved. Bionicle is kinda sorta a Generational story in the same way stuff like Star Wars, Star Trek, Warrior Cats, and the Avatar series are, but it's also unique in that there are eighteen characters who are persistently present, if not always relevant, for most of the shown timeline.
Metru Nui arc, the Toa Metru are the focus, the Toa Mata are sleeping in their capsules, and those would will eventually become the Toa Mahri are also there in the city living their lives, just offscreen for the time being. Mata Nui? All three groups are there. The Turaga giving their hard-earned wisdom, the Toa Mata being their awesome selves, and the Matoran providing support in their own way. Then in Ignition's first two years, it's the Toa Inika/Mahri in the spotlight with the Toa Mata doing the support work and having their own adventures elsewhere, but the Turaga are also still around to send them out in the first place. And then in 2008 the Mata come back in to finish things off, since the Mahri have finished their mission for the time being, and the Mata still have to complete theirs. It's a little janky, admittedly, but it doesn't actually feel that forced when you really think about it.
So in that way, I kinda like the near-infinite lifespans thing, because it means even characters past their prime are still able to contribute and grow, and characters yet to come into their own still have a role to play. Sure, the Matoran->Toa->Turaga thing could arguably be seen as a stand-in for the typical process of growing up and getting old, but I like that the Matoran are already considered adults with their own responsibilities and lives, and in a similar way though they have a more singular purpose, the Turaga can still get involved to some degree. It means that character progression and learning can be a persistent process no matter the form or point in the timeline. (Though at the same time, I also like that the Toa Mata are outside of that cycle, because it cements their importance in the setting compared to normal Toa, and means they can plausibly remain mainstays without necessarily preventing other casts from getting their time to shine.) I do think there are other generational series that can benefit from exploring how stuff passes down and changes over time as older characters die and newer ones are born, but to be perfectly honest I've never been a huge fan of that aside from specific exceptions like Korra.
I do agree here, though. Given the range of emotions and attachments they already possess, I feel like the omission of romantic love is a bit weird. And to get on my tumblr-y soapbox a bit, I'm kinda miffed at the implication that romance and procreation are inherently linked; sure from a historic standpoint or whatever that may be the origin of it, but if we wanted to go strict on evolutionary psychology not applying to robots, then we'd have to throw out stuff like friendship and loyalty as well, which the Matoran and others show in spades.
Mind you, I understand why Greg and large swathes of the fandom would be nervous about its inclusion, from a meta standpoint; to put it bluntly, romance in popular culture tends not to be handled too well, and of the examples I listed up top, Warrior Cats is awful at this, and Star Wars and the Avatar series get kinda soap-opera-ish when it becomes the focus. Star Trek manages to avoid it for the most part since all the main characters are mainly professionals doing their jobs, not adventuring and frolicking willy-nilly, but even then there's still some awkward stuff, especially when Kirk encounters the attractive female alien of the week.
So I definitely get why some people would be afraid that making romance an option would lead to similar bad subplots and forced romances and breakups and shipping, and just in general a huge descent into bad rom-com territory. With that being said, though, I think it can still be a good thing, as long as it's handled well. Keep it low-key, and explore it well when it is present instead of just forcing things willy-nilly because reasons. So like, to see Hahli and Jaller's implied thing develop across the course of the Ignition arc would have been cool, but I would hate for it to turn into some sort of awkward love triangle with Matoro for the sake of edginess, or whatever it is that motivates those kinds of developments in other franchises. (And while I'm on this, I see the Toa Mata more as siblings to each other than anything, so I'd hate the idea of Gali and Tahu or whatever the shippers like to do with those six)
TLDR: The lack of aging is cool because it allows for characters to remain relevant and still grow and learn at different points in the overarching story. (And it also cuts down the sort of 'family tree' shenanigans that could lead to bad romantic writing.) The lack of romance is understandable from the perspective of fear that it's inclusion would degrade the overall writing, but doesn't make sense from an in-universe point of view, and if handled well, could be another interesting avenue from which to explore and develop the characters.