That's a huge set of misconceptions. You should probably re-read what
@akhavr just wrote - this is not about being fair or not, this is simply about how things actually work. I'll try to expand on that a little.
First of all, Dash is not about being a fair or a democratic voting system, Dash is about building the best decentralized payment network where techs and incentives are properly aligned. We don't need a lot of people to vote, we need the most incentivized of them to do so. Decision rights are for those who have the greatest stakes, so that they also have a huge financial risk for making the wrong decision. If stakes/risks are low, bad decisions are more likely to happen because a financial impact of such a decision might be not that significant.
Moving further... You don't use a product because you suddenly receive decision rights on how to develop a better version of it or where should the company that produced it spend the money. You use it because you have no choice (that is the only product you can use, like say your fiat money or a product of some monopoly in your area) or you use it because it's the one that suits your needs the best way possible (e.g. if you need a smartphone, you choose the one on Android because you need to have root access, or you chose the one with the most convenient design, or the cheapest one etc). But you get no decision rights because of the fact that you use it - you do not decide how to change mobile OS, or phone design, or shipping prices, only the company that produces this specific product decides. Dash is clearly not a monopoly, it tries to build the product which is easy to use i.e. the most convenient. And so, the same idea applies here as well, the fact that you simply use Dash gives you no decision rights about its future or how to spend the budget. You still can influence it indirectly however: if you don't like Dash - just stop using it and use smth else which is presumably better in some sense already or you think it could become better than Dash in the future. It's really easy to switch to another asset these days. If enough users are going to do this, that would be a clear signal to MNOs that they are probably making too many wrong decisions (or maybe not making right ones at all). Or you can make a proposal and influence Dash's future this way, there is no need to be a MNO to submit a proposal.
And finally, "MNOs are only going to vote for features for themselves"... I think you need to understand how incentives and consensus really work. The idea that shareholders who make decisions about the product design and how to spend company's money are going to design the product for themselves and going to be the only ones who are using it is simply wrong. Such company would end up nowhere but bankrupt and shareholders are going to loose all the money. The whole point of any company is to build the product which many people _outside_ of the company will find useful. If MNOs or miners are going to use their power to build a product which suits them only and nobody else, then Dash is not going anywhere, we are done here, nothing to see, everyone can go home right now. Fortunately that's not how it works. Every group I mentioned do have some extreme conditions in which they could increase their income or influence in a short period of time if they don't count everyone else. However, since they can't exist without each other (and without exchanges, community, devs too) they have to come to a compromise which moves _everyone_ forward (i.e. consensus). So the real incentive here is not to maximize your income or influence at all cost, but rather to find and follow the best solution that suits majority. That's why miners upgraded when they were asked to share their income with masternodes (slowly increasing their piece of block reward, starting from 20%). That's why both miners and masternodes upgraded when they were asked to share parts of their income with the budgeting system aka treasury (and btw, masternodes went from initially scheduled 60% of block reward down to 45%). Both upgrades required old "privileged" party to sacrifice some of their current or future income in order to move network to the next level. Both upgrades clearly were right decisions in the long term, even though in the short term they looked like quite a serious loss for some particular group. Both upgrades clearly were beneficial to end users who had no masternodes btw.
