This is an entirely valid objection. Not everyone can stomach screen violence, and there is no shame in that. Looking away is a valid response. Not watching is a valid response.

I'm fairly robust in terms of what I'll watch, but even I wince in some violent films. During A Prophet (a pretty much flawless masterpiece by the way), I was hiding behind my fingers during the razor blade murder scene about twenty minutes into the film. Did it really need to be that brutal and bloody? By the time I reached the end, I was forced to conclude that, in the context of the film, the answer was yes. Softening it would have damaged the film. However, that didn't mean it wasn't tough to watch.