But it's not win-win-win when somebody can propose something that exclusively enriches a certain few people
Out of interest, do you have a particular proposal in mind ?
Here's the list.
https://www.dashcentral.org/budget/completedIt doesn't matter whether it is happening now with the current proposals, just the fact that it is theoretically possible makes it a problem.
How is it "theoretically possible" ?
The only theoretically possible scenario I see is owners setting up proposals to pay themselves for doing work that doesn't have a favourable impact on the coin's future. But there would appear to be at least 3 aspects of the stakeholding that prevent that from happening:
1. There isn't a sufficiently large coherent holding group to dominate the voting in that way. (Even though people put about that Evan / Otoh et al own this & that - the fact is they don't. They can be outvoted at least 4:1 even by the most generous estimates of their holdings. By my observations it's more like 8:1).
2. There's nothing that anyone can do in terms of the protocol - even if they did dominate the voting - that doesn't still require a mining majority. So voting could say "do this", devs say "ok" and it still doesn't get adopted because the miners rejected it
3. Even if there was such a hypothetical way for an interested group to 'enrich itself' as you say then commercial pressures would start to manifest. The group can only pay itself in Dash, not any other currency, that is the catch. The wider community can therefore still mitigate said 'enrichment' because it has control over exchange rates
It's therefore far more profitable for 'interested parties' simply to do something beneficial for the project and get paid in a high value coin. (Which is what they are doing

)
I understand that the incentives are all generally aligned -- to make DASH go higher in value. But that doesn't keep people from voting to give money to themselves or their friends.
Basically,with all of this talk of Governance, Dash is turning itself into kind of a corporation. The MN owners are like stockholders, and the big MN owners (hundreds of MNs) are like the Board of Directors. If a proposal is ever put before a real-world corporate Board of Directors that could be self-dealing (e.g. a business deal with a company that is owned by a family member) or a conflict of interest (e.g. introduction of a product that might negatively impact another company, that the Director also has a substantial interest in) then they have to recuse themselves from the vote. It's a simple ethical concept. If Dash is trying to portray itself in this way then the power players of Dash need to make a very public effort to make everything above-board and ethical -- and that includes abstaining from voting where there might be any conflict of interest or self-dealing, or even the perception of such. Accusations of cronyism can quickly kill this golden goose. They would be wise to avoid them at all costs.
Just glancing through the approved proposals, I didn't notice any that mentioned getting competitive bids for any given project. It's always "We've retained XYZ" at a given price, and I understand that's an easy thing to vote up or down, but really for a big project there should be a budget set, and then have various competitors bid on it, and the bid that provides the best value for the amount budgeted should win the project. This is just a basic principle when running a large company, which Dash is looking more and more like.