IMO this is pretty rational. Mistral is 'smart enough' for lots of applications, very fast, and embedded in a regulatory environment that people find more trustworthy.

It's not exactly hard to see why people might feel that relying on an American or Chinese provider is a major liability.

I am a Mistral Le Chat Pro subscriber. I specifically chose to test their offerings because they are European. I don't have the necessary local hardware to run really big models, therefore need to choose a cloud provider if I want LLM action.

I find the antics of Anthropic, OpenAI, Google, Microsoft distasteful and avoid their products where I can.

After testing Le Chat and Devstral-2 for a while, I felt their offering was good enough to stump up some cash for it. I appreciate that many of their models are open weights and Apache 2.0 licensed. In general, I've been happy enough with the service and quality.

Maybe others are better, but I have little reason to change right now. If curiosity gets the better of me, I'll be looking at Qwen, Kimi, GLM, Deepseek, other open weights models, before Anthropic and OpenAI.