Nobody complains about gentrification because some hipsters moved to neighborhood, or even because they opened one of those atrocious coffee shops. The main complain is that the, intended or not, result is that low-income people, the people more at risk in the country are thus driven away from historical neighborhoods and pushed more and more to the margins (both literal and figurative) of society.

BTW, some ironic thing I've noticed is that many people will retort with "Well, that's how the economy works, supply and demand and all of that, besides, the original owners of the properties will make bank", but when the same dynamics is done to them by rich foreigners buying houses in western cities and driving the prices to the sky they scream murder.