It is odd. Now NASA has released an official statement denying the claims.

The sulfur sigs are not 100%. The instrumentation they are using isn't sensitive enough to say with absolute assuredness. However, they are good enough that most scientists believe it's sulfur, and that it's indicative of life.

I think all of this has to do with some weird culture in the pop science community that is hazardous to new ideas and causes scientists to be very guarded with their theories, and even concrete results.