Frontlines having an oddly long queue isn't too new of a thing, but it's something that has been exacerbated immensely by the release of 2.5. The lengths of the queues are sporadic, for no rhyme or reason, but generally tend to lean on the long side; I can go from getting matches after waiting only 5-10 minutes, to sitting in queues for over 45 minutes and getting nothing, even if I were to queue immediately after getting out of a previous match, much like I'm doing right now.
Some of these long queues make no sense either. A single slaughter match is, at maximum length, fifteen minutes. So to be in queue for over 45 minutes, means that approximately three Slaughter matches have occurred, possibly more depending on the size of one's data center. Am I really to believe that there were 216 (72*3) people in line ahead of me, and that only one game happened at a time?
To amplify this further, when the queue finally does pop (if it does pop, before I decide to just say "screw it" and do something else), there's a high chance that it's not even the 72-man frontlines that I wanted to do, and instead the abomination that is known as 24-man. 8v8v8 is not "more fun," it's more boring. I didn't wait in a queue for nearly fifty minutes to do something boring.
Getting back on track, these queues times are simply just unacceptable, there's no reason a person should have to wait such a ridiculous amount of time to get into content. I average about one game per hour, two if I'm lucky, and these games themselves only last about 10-12 minutes. The rest of the time, I'm spent doing very little else, because god knows if I afk for even a minute to take care of something, I could potentially miss the sporadically random queue pop, and then guess what? Back to the beginning of another 30+ minute wait I go!
These problems aren't unique to solo vs. premade either; I've experienced stupid long queues both by myself, and when trying to queue two or three friends.
So what causes this?
Is it lack of people?
Well, okay, that may be a possibility, but I'm inclined to think not so much because I've gone from getting lucky and getting three fast games of queue times of about 10 minutes, to then sitting for over an hour without a pop, even when queuing again directly after finishing the previous one. And this is in prime time, on a weekend, when the number of players should be at its highest.
But I'll play devil's advocate a little too, what if it is the number of players? Well, in that case, why are there data centers to begin with? Why can only certain groups of players do stuff together? It's no surprise either that this game just about dies at night (11:00pm to 6:00am, PST) since most people are asleep. Yea, sure, there's a fairly large number of nocturnal players, but not much they can do together when they're separated by said data centers. I've always thought of MMOs as something you can play 24/7, and there'll always be enough people to do stuff with, and that's just simply not the case with the game as it currently is.
Is it the split game types?
Well, that does seem more likely. With the introduction of Slaughter, we now have two possible modes for Frontlines, and that's very expectedly driven a line through the middle of the Frontlines playerbase, making a faction of those who prefer Secure, and a faction of those who prefer Slaughter. This kinda ties in a little bit with the lack-of-players bit from above, I suppose, but this basically means both types now have a smaller pool to choose from.
Is it the algorithm?
I think this is the most likely culprit; I think the design SE has put in place for matching groups is probably just wonky and convoluted as all hell. What it should be doing is laying out slots for all nine parties in a frontlines game, then grabbing from the front of the queue. "Oh, this premade of four wants in? Okay, their party now has four slots remaining. Oh, a premade of two. Well we can throw them in with the four to give them six. So we can fill them up completely with a set of two, or two solos." That kind of stuff, but instead it seems to just do something completely different.
It also doesn't help that if enough time passes it will instead try to make a 24-man instead of a 72-man to "get the ones who have been waiting" into a game. But how does it determine this length of time? Is it based on the players? If you have 24 people who have been waiting "long enough" that you make a 24-man, chances are you also have enough on the sides who are queuing and want a 72-man game, so why not just make the 72-man? It makes literally zero sense.
Whatever the case may be, this is something that seriously needs to be looked at and fixed. I know they tried with the whole Frontline Roulette, but that has honestly not done a damn thing, at all.