I disagree with that.
The fact is that most multinational companies partake in dubious practices.
How many of them do you boycott?
do you:
drink products manufactured by coca cola? (deeply questionable practices both in terms of water consumption, employee rights in the developing world, and distribution of coke to countries and encouragement of it being used as a drink for very young children)
Tesco? (the word attempted monopolisation springs to mind).
apple? (again deeply dubious practices esp in factories in China, and employee suicide rates are considered some of the highest in any multinational company).
any high street clothing retailer (who on the whole make use of sweatshops in the third world in order to produce cheaper clothes)
the list is, in fact, endless.
And in truth nestle is virtually impossible to boycott since their market extends well beyond that of "snacks" into other areas such as beauty, and unless you are prepared to maticulously go through every product they produce, and keep up to date on those they have a hand in, it just isn't plausible to do so.
Even the own brand products that are similar to those of nestle are generally manufactured by nestle, so people who say "oh I buy own brand," are generally still buying nestle, they just don't realize it.