I fail to see how this is a surprise to anyone. Marc's in the prime earning potential part of his career (certainly regarding being involved in young companies that might make it big), and it's patently obvious that Jolla is going absolutely nowhere quick.

I was never hugely sold on him (or any of the executive team), but he can clearly find employment elsewhere in the tech sector that will bring him far more financial and tangible success than Jolla is likely to in the forseeable future, and be far better for his career. For someone like him, staying on too long at at a company like Jolla can be quite damaging to both reputation and career prospects.

Best of luck to him.