What does "diversity has more of a purchase" mean?

Question

The following is an excerpt from the Japan Times article of June 15 regarding "hikikomori" (social recluses).　

According to U.S.-based journalist Makiko Iizuka writing for Yahoo News, new labels are always being introduced in Japan and they invariably create negative stereotypes: “parasite singles,” “freeters” (young part-timers who are not students), “hinkon joshi” (destitute girls) and so on. News outlets cling to these terms “with a sense of titillation,” she writes, making them “trendy” and establishing them as behavioral predictors that exacerbate prejudices. Such labels tend to be suspect in the U.S., where 〈diversity has more of a purchase〉. In Japan, however, the public is receptive to them, and they are sometimes used to describe people who may not display many of the attributes affiliated with a particular label, if only for the sake of convenience.

What does diversity has more of a purchase mean in this context?

Answer 1

As @tchrist suggests, purchase has a meaning that, while familiar to most native speakers of English, is far-removed from the more common meaning. Oxford/Lexico:

[mass noun] Firm contact or grip.

‘the horse's hooves fought for purchase on the slippery pavement’

[in singular] ‘an attempt to gain a purchase on the soft earth’

"Diversity has more of a purchase" is saying that the concept of diversity has "taken hold" in the US more than it has in Japan. It's not a particularly idiomatic use of the word, but its meaning is reasonably clear to most native English speakers.

Answer 2

I will say that "more of a purchase" is hardly ever used, and sounds strange to my (American) ears at least.

My mind connects it to the idiom "to buy in":

2. Fig. to agree with; to accept an idea as worthwhile. The committee liked my proposal and decided to buy into my plan. Do you think you can get the whole board to buy in?

In America the idea of "embracing diversity" is mostly "bought" by major media outlets as well as a large portion of the population. There would therefore (probably) be outrage if one of those outlets wrote something that explicitly said "[certain labeled group name] is bad and commits crimes often."

This is especially true if the group label was defined by race/nationality/gender/sexuality.

I will put a couple caveats though:

1. This type of naming is pretty common for "generations." Millenials and Generation Z are shamed by the Baby Boomers, and vice versa. This isn't considered too outrageous.

2. If the news outlet is particularly left or right leaning, these rules sort of go out the window.

3. While explicitly this wouldn't be appropriate, implicit stories wouldn't get the same kind of response.