Shoplifting is tough because it can often be cheaper for the store to write it off than to sufficiently improve security. I think a misdemeanor for theft is fine, but I agree that these laws should be enforced.
It's unlikely that a shop would seek enforcement if it could result in a violent altercation and scare away customers. Likewise police are more likely to expect violence if they are only called in dire emergencies.
A friend worked at a Macy's in Nevada for a few years. Staff were told that shoplifters should be assumed to be armed, and that security would not normally confront them. Staff would often stand by and let shoplifters walk out the door with big hauls of stuff. Large daily losses to theft were just budgeted for.
I saw a 160lb security guard tackle a 90 lb woman who was probably in her 50s; that was freaky enough. I can't imagine one with resistance.