The upside of the `Like` representation over the custom activity representation is that reactions can at least be interpreted as plain `Like`s even if the recipient server doesn't fully support the reaction feature.
The downside, on the other hand, is that, well, the reactions are interpreted as `Like`s if the recipient server doesn't support the reaction feature, even when the reaction doesn't bear positive intent at all (e.g. the thumbs down emoji: 👎).
But I think the use of reactions for such a negative purpose should be discouraged in the first place, as I can hardly visualise negative reactions leading to constructive consequences, and I'd argue that keeping users aware of the possibility of reactions being recognized as plain `Like`s is actually good for health of communities. If you want to express disagreement with an opinion, it would be more productive to argue against it with your own words or simply share counterarguments if somebody else has already made ones,
@tesaguri Many commonly used reactions are neither likes nor dislikes, for example 😡 😕 😢. I think discarding them completely is better than falling back to 'like'