Hovercards are currently set to only show on main namespace pages (articles). This is because other page types would require custom treatment that we are not yet ready to invest in supporting until we ensure that the primary use case is providing value. However, while this is the case, we should probably remove hovercards from the commons beta menu since it does nothing.
My guess is that it is so rarely usable that it is a distraction. When I search the event logs for commons hovers I got this (query below):
Commons had 100 hovers and 4302 users), which is equivalent to:
enqikiquote, 160 hovers from only 198 users
eo.wikipedia 112 hovers from 98 users
pl.wiktionary 92 from 44 users
Clearly, the ratio is off. I would guess that 4302 is the number of people who tried it and never turned it off.
SELECT count(*), wiki FROM Popups_15777589 WHERE (event_action = 'dismissed' OR event_action LIKE '%opened%') GROUP BY wiki;
@ovasileva good call and great question. All the wikis have it as an option, including wikidata! At some point, we might want to run through and confirm there is value before enabling- I had thought we would only want to enable as default on Wikipedia, but maybe it is more of an open question.