I think this attitude is harmful to everyone involved - 3CX, resellers, and end users.
Limiting 3CX - less partners pushing 3CX means less exposure for 3CX in the market. No matter how much 1 person is offering 3CX, they will never have the reach of 2 people.
Limiting resellers - not only is this a "pull up the ladder after myself" approach, but it stifles innovation. With more partners in the market, you have to demonstrate your value better which means you find new ways to present it, which is a win for both you and the end user.
Limiting end users - they will have less resources to help them with all aspects of 3CX (implementing, upgrading, supporting, enhancing, etc.)
Look - 3CX sells direct and has no plans to change that - so any person who doesn't see the value in going with a partner will just avoid the partner all together - no matter how limited the partner choices are. You won't be able to win business on the approach of "I'm the only option here"
I don't know your market as I'm US based, so it's possible I'm missing something here.