If you don't know, they've announced that they'll retire Dominion . They wrote that there are small fraction of players playing the mode, not enough to sustain it, and that the map is imbalanced, well, not balanced enough to satify them. According to them, "When it comes to the resources required to keep Dominion permanent solve the inherent design problems give it ongoing live balance support, we’ve consistently devoted them to Summoner’s Rift and related features because we felt they’d improve the overall League experience more." They'll disable the mode at 22.02.2016
Where to start?
First of all, there are small number of players playing it. Why? Well, since it got released, there is no ranked mode. None. At least ARAM is random, fine, but Twisted Treeline has a ranked mode, so why not make it for Dominion? It woundn't that hard to do it. They said then they would do it. And to top it off that, no Champion Mastery points for this mode, and any other mode/map other that Summoner's Rift. Riot didn't made enough effort to sustain the mode, that existed for 4 years. That is a long time in League's years.
Second of all, most of you will write that it has a long queue. Guess what? Team builder had it. Twisted Treeline had it back in a day. Hell, new queue can last a long time, especially the new ones. So long queue are nothing new.
Third of all, it is 2016, and Riot is a big company now. A really big Company. And they can't sustain a mode? Really? Not even to improve it over 4 years. They completly forgot to eve Oh wait, I forgot, they had a SINGLE event based of Dominion, called Ascension, and it SUCKED.
Why? Because it amplified any problem Dominion had, and multiplied it. It was, at best, an experimental mode. The champion picks were even more limited, so bruisers and assassins were in every game, in full team composition. Just them, not mages, not supports, and not tanks. And keep in mind the state in that season and how chaotic champions were at the time. And the disappointing storyline to add, and you have a mode that quickly came and went.
Speaking of, the gameplay of Dominion. Some might say that Dominion strategy is the same: 4 top, 1 bot and hold. No evolution of that. I say, maybe, but the strategy of Summoner's Rift is nearly the same: 1 jungle, 1 top, 1 middle and 2 bottom lane. I'm not specifing the roles because, on Dominion, you can make the best of it, like on Summoner's Rift, where, for example, now more and more supports get damage items. In fact, Dominion seems more balanced than Summoner's Rift now than ever.
Like Summoner's Rift and Twisted Treeline, Dominion has it's own champion tier list. There are some champion that sucks on Summoner's Rift, but they do great on Dominion, and vice-verca.
And there is also the marketing. There are none to speak of. There always has to be a new fresh thing to keep customers in. Featured game mode ain't cutting, since they're events that don't stay. And now Dominion will be added to that list. And also, Riot didn't do anything to keep it fresh and new. There were some balancing patches, but nothing major, well, aside of ascension. Not even marketing other maps to LCS/esport fans. It is always the same map. Last time I checked, other games(same or other types of games) that are for esports, put additional maps on the plate, just keep diverstity in their gaming.
Does Dominion deserve a rework though? Yes and no. Yes, as in updation of Crystal Scar, it's texture, models and overall theme, to match whatever new lore has for Crystal Scar. However, I'm afraid much more for gameplay, that they will make it similar to Summoner's Rift, similary what they did to Twisted Treeline. I'm not a expert for Twisted Treeline, but Riot seems to want it to push-based map, like Summoner's Rift is, especially with 2 towers and Vilemaw's buff.
This is a tragedy for me because I wanted to compete on Crystal Scar on my NA. At the time, I didn't have enough time for a full game on Summoner's Rift, so I started playing Dominion instead. And I love it. Now, I predict that it will have less player base once they make it into a featured mode. I do hope they redesign it, and return it as a mode. But, with failed reworks on many champions, and questionable decisions, who knows?