Srimate Ramanujaya Namaha!
In Ramayanam, when we look at the point of view from Kaikeyi’s side, she was thinking that she was doing good to Bharathan, but eventually ended up regretting it later on. So both she and her son suffered for this. Bharathan is a devotee of Sri Ramar.
Now coming to Vaduga Nambi’s story, he carried Udayavar’s sandals in the same bag as the thiruvaradhanam deity, seeing which even Udayavar was shocked. Here also, Udayavar is a devotee of Perumal.
Both Bharathan and Udayavar didn’t encourage Kaikeyi and Vaduga Nambi to do what they did.
Kaikeyi is thinking of doing sevai to Bharathan (a devotee) but gets a bad name to this day. Vaduga Nambi is thinking of doing sevai to Udayavar (also a devotee) but is being praised.
How do we understand this, swami?
(Adiyen know that this is not a good comparison, but still, this was in adiyen’s mind for a long time. Kshamikka prarthikkiren.)