My philosophy is, in a game heavy on narrative at least, if I'm going to be spending hours in the company of a protagonist then they better be interesting in some way or another.
Silent protagonists are just rubbish. They have no personality, they offer no insight to their situation or surroundings and they're inconsistent with the world around them. They're just there. An empty vessel standing cross-eyed in silence while the supporting cast do all the heavy lifting does not make for a compelling dynamic between team members. They're a fossil of old-school game design and they need to be eradicated.
It's not exactly a deal breaker, and I can still enjoy certain titles in spite of them, but games are getting longer and more reliant on dialogue now, and my tolerance for them is waning as the years roll on. Thank god the likes of George Stobbart, Kat, Kazuma Kiryu, Nathan Drake, Cloud Strife and April Ryan are full-fledged characters, that's all I can say. If they weren't then the quality of the games they featured in would be severely impacted.