What Dominion should have been
So if you were going for a game mode that appealed to those Call of Duty players, and people who just want action all the time with buildup, you fucked up with Dominion. But you know that, that's why it's gone. But you probably have no idea why it actually failed, being that you're Rito games. Let me tell you how it SHOULD have been done.
If you're appealing to these types, you have to understand what it is about the normal league games that they don't like, and move away from that. Dominion was supposed to be this all action all the time arena where farm was put on a backburner. So why even have minions on a map like this?
The objectives in dom were actually appealing, sort of like a king of the hill type deal, except for how minions interacted with them.
So here's how I think this should have went:
Remove all farm. No minions. Everyone starts at level 18. Either no item shop or items cost nothing (no potions in shop). There is no snowballing. Keep king of the hill type objectives perhaps, or perhaps a first to 50 kills wins type deal. This is the call of duty game mode that they wanted. No farming, no falling behind, no snowballing. You can kill a guy who is 30-0 if you're 0-10, wouldn't matter, it all just depends on mechanics and playing skill.
Now how did you fuck that up Rito?
So just try it. Take a weekend for extra game modes and let's see how it fares. Wouldn't take much effort, hell you can use the SR map if you want. Make the minions not spawn, remove all towers / nexus / inhib (or render them moot somehow, if they're visually there it's a non issue, as long as they take no part in the game itself) because it has no part to play. Everyone starts the game at max level with infinite gold (remove potions from the store for this game mode). First to 50(?) kills wins. Wouldn't even be terribly hard to program. Boom, instant late game action right from the get go. And you don't have to call yourself a feeding idiot every time you die, because it doesn't actually matter. And toxicity in these games modes shouldn't really exist, I'd be surprised if it did.
This game mode would allow people to practice mechanics, teamfighting, full end game item builds, all without the stress or fear of fucking up one time in lane and spending the next 20 minutes to an hour paying for it.
Just try it.