There are several historical evidences to prove that it was Kamma's the original suffix holders of the honorific title 'Naidu' not just in Andhra but in Tamil Naidu, Karnataka, Maharastra and else where, but over a period especially starting from the 19th century several Kapu communities started attaching the title 'Naidu' to their names as a suffix to raise their social rank.
They reportedly argue that anyone who owns the land can be a 'Naidu' as they too own small amounts of land in Andhra they claim the tag Naidu to their names!
If you check their children (Especially Kapu's) on various Telugu matrimonial sites, they'll mention their caste as 'Naidu' putting aside their caste which is Kapu/Balija/Munnurukapu /ontari, despite the fact that 'Naidu' is not a caste title but a honorific title for the leaders...!
Especially Kapu's started adapting the title to their names through there are no evidence to prove that they are the original/ancient title holders of the above honorific title...!
Eg:- You can just google 'Naidu Matrimony' in the Internet you'll see a flood of websites popping up and most of the profiles say they are either Balija/Kapu/Telaga/Ontari/Munnuru Kapu by caste upon cross checking with them, therefore always ask for the caste before jumping into conclusions of someone bearing a title 'Naidu' to their names, thank you.