One of the reasons I got into marketing was that I always saw it closely aligned with business strategy. At the time I was narrowing my focus to marketing in business school I was taking strategy classes as well, and the complimentary nature of that coursework accelerated my learning about marketing and helped me gain a great perspective as I entered the world of marketing after school.
When you think about business strategy, it's about identifying an unmet need in the marketplace and employing skill and service to meet that need in a better or new way. Whether it's a new product or service line for your company or a brand new offering to market, the ability to gain customers and communicate your value proposition in the market is first and everything else that operationalizes that pursuit comes after. The heart of that mission is marketing and even thought business owners try to trivialize marketing at times as promotion or "making things look pretty" the impetus to meet the market at its point of need is where marketing and strategy interconnect.
I'm sure people in the other functional areas of a company feel like they are at the core of strategy for their company. Finance, operations, sales or even accounting can hold the power at companies depending on their history, leadership or business focus, but the strategy end really does come from marketing. Without the market insight, customer input, communication channels and brand understanding the rest is just window dressing.
If you don't like that answer, I'll defer to Peter Drucker, the father of business consulting:
“Because the purpose of business is to create a customer, the business enterprise has two–and only two–basic functions: marketing and innovation. Marketing and innovation produce results; all the rest are costs. Marketing is the distinguishing, unique function of the business.”
So if you're in marketing rejoice in the knowledge that you are helping your business build its strategy. In my opinion there is nothing more valuable you can bring to an organization.