Shawn's team considered the option of making other products, but then they dismissed it, or decided that it was not a good idea.
For example, you might consider the idea of going to the state of Alaska for your winter vacation, but after looking at the temperature in Alaska during the wintertime, you dismiss that idea - you decide not to do it.Finally, Shawn says, "We believe that we should stick to our core competencies and improve the product we currently have."
"To stick (stick) to something" means to continue to do something or to use something."To stick to something" means not to change what you are doing.
For example, you might stick to the same kind of toothpaste for many years, meaning that you continue to use that one kind of toothpaste - you don't change.Shawn wants to stick to, or to continue to use, the company's core competencies.
A "core (core) competency (competency)" is something that your company or business does very well, or something that the company is known to be an expert in.One of Vision Corporation's core competencies is producing, or making, this product - that's what they're good at.
That's why Shawn thinks that the company should stick to, or continue to make, the current product, improving the product instead of deciding to make a new one.