Panchasamaskaram can be termed as a ritual; samaskaram means refinement, and it grants the eligibility to perform the ritual. Panchasamaskaram grants the eligibility to serve Emperuman.
We acquire the eligibility to serve Bhagavan through Panchasamaskaram. Why should we serve Bhagavan? Because he is our goal. One has to serve Emperuman like a wife serving her husband. We should serve lovingly and with the thought that we are born to serve. We should serve to his pleasure, hence panchasamaskaram.
Materialistically speaking, when a favorite person visits our house, we cook his favorite food and we earn the required things to cook the food with care. Similarly, Bhagavan is our favorite, to serve him with care we have to make ourselves eligible through panchasamaskaram.
It is certainly wrong to prevent others from becoming a Srivaishanava.
With Acaryan’s permission, one can render prapatti without panchasamaskaram but follow the ordains of Acarya.
It is said that as per Tenkalai tradition, prapatti is done along with panchasamskaram. We need not assess whether Thenkalai sect performs prapatti along with panchasamaskaram.