Not sure what kind of "tough love" you're referring to specifically, but if you're talking about the healthy way to deal with loving an addict, setting boundaries, sticking to them.. not making threats.. then yes, I think it helps, if anything, it helps the folks who love the addict live their lives unaffected directly by the addicts behavior. Often a bottom is "created" by families during interventions to guide a person into accepting help.
However.. I see both sides. If anyone would have done that with me, I likely would have been just fine telling them to **** off and get out of my life, and continue using/drinking. I am the one that had to want help, until I did, it wouldn't have mattered what was said to me.
Boundaries aren't created to 'get the addict help', they're created to help the folks who love an addict live in a healthier and non enabling way.