Ideas change. Apple didn't start with iPhone or iPad. They started with the Apple I, which was just a circuit board. Microsoft didn't start with Windows 7. They started with BASIC for the Altair. Paypal didn't start with online payments. They started as money transfer between PDAs.
As for the criticism about "X for Y", the problem is not with them, but with the rest of us. Most people (smart or not) have a hard time grasping completely original ideas, and they don't have the time to dive deep into it. "X for Y" is simply a low bandwidth way of transferring a core idea. It's the MVP of communicating your vision. If you have to take more than a sentence to convey your idea/startup, you're going to have a hard hard uphill battle. But chances are, you don't have a clear understanding of what problem you're solving.
As for the criticism about "X for Y", the problem is not with them, but with the rest of us. Most people (smart or not) have a hard time grasping completely original ideas, and they don't have the time to dive deep into it. "X for Y" is simply a low bandwidth way of transferring a core idea. It's the MVP of communicating your vision. If you have to take more than a sentence to convey your idea/startup, you're going to have a hard hard uphill battle. But chances are, you don't have a clear understanding of what problem you're solving.