If you own a large amount of value or wealth that you did not create, I would say that is undeserved.
Founders and early employees contribute work and are hopefully rewarded for that work with ownership stakes in the company. Rightly so. But as the company grows, and to the degree that it necessarily hires additional employees, the proportion of ownership held by these early employees becomes undeserved (in the simple above sense of the word). Their large ownership positions remain, even as it becomes clearer and clearer that the value of the company is created by its hundreds/tens of thousands of employees.
So if you start a business and make a profit (a hard thing to do!), that is not undeserved. But if business grows and eventually the value is created by 15,000 people all together, you don't deserve 25% of it.
IMO, you do since you created the company and navigated it through the difficult early waters. If you were able to do so and maintain a 25% ownership share (astoundingly unlikely/uncommon IME), then you "deserve" it partly as a founder and partly as an ongoing investor (by virtue of not selling your shares).
There's a genuine argument that the investors and risk-takers "created" a portion of the wealth by virtue of bankrolling and hiring those 15K employees and paying them a risk-free salary.
I'm not especially interested in whether or not it's cosmically fair when deciding whether or not it's deserved. Warren Buffett "deserves" every bit of Berkshire Hathaway that he owns; Bill Gates every bit of Microsoft, Mark Z every bit of Facebook, etc. (Again, all in my opinion. I'm sure there are others who disagree, but even among them probably differ on how [or whether] to correct the "undeserved" ownership.)
Founders and early employees contribute work and are hopefully rewarded for that work with ownership stakes in the company. Rightly so. But as the company grows, and to the degree that it necessarily hires additional employees, the proportion of ownership held by these early employees becomes undeserved (in the simple above sense of the word). Their large ownership positions remain, even as it becomes clearer and clearer that the value of the company is created by its hundreds/tens of thousands of employees.
So if you start a business and make a profit (a hard thing to do!), that is not undeserved. But if business grows and eventually the value is created by 15,000 people all together, you don't deserve 25% of it.