We often promote local tour agents here (not the same as "travel agents" - that is a different thing) and we did allow you to mention your own business.
I just wrote an article about Viator which also books independent tours in ports of call.
So - don't be so defensive. What people say about "safety" in terms of not missing the ship is absolutely true. I realize your services only have a very small risk factor, but any risk factor at all is not as good as no risk factor.
So - many people yse tour agents like you and save plenty of money. But some people will always stick to ship-provided tours. That's just the way it is.