The new vogue for accusing people of 'virtue signalling' (Sam Bowman comments that 'showing off' would be more accurate) can be juvenile and irritating. But there are more serious issues here.
Since political ideologies carry moral claims with them, it is normal for campaigners to be claiming some virtues, even as they dismiss others. The hazard comes from labelling people as hypocrites (even if the charge is correct) unless they go all out like Greta Thunberg at one end or far right populists at the other. It is not just impractical to expect everyone to be an activist; that can also encourage the disease of arrogance to which activists of all colours are liable.
Even worse would be to push us into 'vice signalling' instead. The flamboyant amorality of certain rock stars, entrepreneurs, or publicists can seem entertaining before it becomes wearisome. But once we get to proper evil, be it personal or social and political, things are not entertaining at all.