Assume for a moment that acquiring companies don't understand what organizational practices/structures make the companies they're acquiring productive. (If they did, they'd just build an internal team that does things that way.) Assume that, instead, "acquisitions" are basically a feudal transfer of power: a different knight is now collecting the taxes from the serfs, but neither the new nor the old knight understands how wheat is grown. The serfs are a black box, and a fragile one. If they want to continue to bring in taxed wheat, they have to mostly leave the black box to its business, rather than poking around inside it trying to change things they don't understand.
Under this paradigm, you can sell a co-located team to an acquirer, and it'll retain most of its productive value, because it's very easy to just "leave the serfs to their work": you just keep the same people working together in the same office. But you can't really sell a team with mostly-independent foreign subsidiaries to an acquirer, since the process of absorbing those subsidiaries into the corporate structure will naturally (for legal + political reasons) tend to force restructurings of such subsidiaries. The black box would have to be taken apart—and since the acquirer doesn't trust their ability to put it back together in working condition, they just don't want to buy it at all.
As well, a colocated team can be acquihired for the purpose of pilfering specific members of that team for ones' own org, while discarding the rest. This possible use increases the saleable-asset value of such teams. A foreign-subsidiary team cannot really be pilfered in such a way, unless the acquirer happens to also have a foreign subsidiary of their own in the same country, which they'd benefit from transferring the acquired employees into.