Anthropic gets heat for being the only major AI lab not supporting open models

Anthropic is facing criticism for not signing an industry letter backing open-weight AI models while rivals including Nvidia, Meta, Microsoft, OpenAI, Google, and SpaceX publicly endorsed the stance. The dispute highlights a growing split in Silicon Valley over whether AI model weights should be openly downloadable, especially as Washington weighs restrictions on certain Chinese models. Critics argue Anthropic is protecting its commercial position by favoring gated access over open release. The debate has intensified after Chinese open-weight model Kimi K3 showed strong benchmark performance and after U.S. officials floated possible sanctions on Chinese open-source AI if distillation from U.S. models is proven. The story suggests increasing political and competitive pressure on closed-model labs, with open AI positioning gaining momentum in both cybersecurity and policy circles.