A senior student in my dojo once said he looked for two signs of a "healthy" dojo:
1. A place where students being taped up, bandaged, or off the mat for injury was a rare occurrence.
I don't know, I'd want to know more... For one thing, how serious the injuries are. Bruises, wrenched fingers, or pulled muscles might benefit from a bit of first aid, but I would not personally consider them a catastrophe.... I got my toe-nail torn off once and it was unpleasant and took a while to heal but it's not like there were any long-term consequences or anything. Another question would be who's getting injured? To me it seems more concerning if beginners are getting injured more than seniors, as that suggests they're being pushed more than is safe for them or that people are (either intentionally or due to ignorance) taking advantage of their inexperience or willingness to do as people tell them to.
But if two seniors want to train a little nearer the edge of safety and do know what they're doing and aren't pressured to train that way and don't pressure anyone else to train that way, and in doing so risk an injury? I don't know, seems like it's their life and body to do as they like with....
Most people who do any sport do from time to time get some injury, whether it's running, swimming, basketball, etc. Hopefully it's not a very frequent thing and hopefully the injuries are not major nor hard to heal. E.g. there are some things the body can fully heal, and other things where you're doing long-term damage.
Personally for me I would be less concerned with the actual _number_ of injuries so much as how free any person is to choose how far to push themselves and to opt out of things they consider riskier without any pressure or embarrassment. It really bothers me if there's an environment where people don't feel comfortable saying they don't feel comfortable...