Telling a business not to focus on profit is asking them to consider failing. You might as well say, "hey, how would you like your business to fail? Try this then!"
I get your sentiment, because you love Dominion and it's outdated. It's a shame when a game you really like suffers. That sucks. But the reality is, most players don't like Dominion. I'm one of those players. I have played one game of dominion, didn't like it, and never looked at it again. That's probably how most players are, if I had to guess, based on Riot's lack of interest in that game mode.
It's difficult to balance an entirely different game mode for champions that are balanced around something else first. Riot would have to dedicate a lot of resources to that, and they likely wouldn't recuperate them. It's, at best, a pretty huge risk, and as a consumer, you can't blame Riot for not taking that risk.
In other words, your rage is misplaced, and your words won't convince a business to do what you want. What you could do instead, is to direct your efforts, in a more positive way, to guys like me. Instead of raging at Riot on the boards, post exciting game clips from Dominion and try to get people to go play it. I could be swayed that way, perhaps, but seeing posts like this makes me want to avoid Dominion. Toxicity isn't going to get you what you want, no matter who you talk to.