The spork is a creative invention. The only problem: Nobody likes using sporks.
Sure, they’re convenient, but they’re not as good as normal forks. And they’re too scratchy to be a spoon.
Even if a spork functioned perfectly, the experience feels like a compromise.
You might see your idea as a creative mash-up, but your customer sees an underwhelming product that tries to do too much. If you’re promising convenience, make sure your customer prioritizes that enough to choose your product.