Pac-Man and Cherry Bim. You may be right that there is a reason in Halacha why singles can’t daven etc. etc. There are numerous sources in Shas that back up your Hashkafa position about singles. That does not give anybody the right to transgress the very serious aveira of Onaas Devarim – hurting somebody’s feelings.
A disabled Kohen cannot perform the Avodah – would you taunt them for their disability?
A blind person according to one opinion is exempt from all the Mitzvos – would you criticise them for their blindness?
Not all singles can be blamed for their position and even the ones who can (and this can only be known by somebody who knows them exceptionally closely)- well there is a correct way of sensitively informing them of this without upsetting them. As the posuk says ‘Rebuke your friend but do not bear a sin through him’ (Sorry I have no Hebrew letters).