Pangalatok a derogatory word?

Some of our fellow Pangasinenses are discussing in the web about the eradication of the word "pangalatok" as refering to the people . According to them it is a slang word that is demeaning and derogatory. They claimed that "pangalatok" means "Pangasinense sira tuktok". They are instigating us to join them and completely remove the wrong usage of the word in any conversation.

What's the big deal? My friends called me "pangalatok" because I speak the language. They don't even know the "... tuktok" as some claimed to be. In the eyes of the people outside our province, most of them know nothing about "...sira tuktok" but of the language spoken by us.

Here's a conversation in a chatroom

Jill: Where are you from?
Jack: Pangasinan
Jill: Pangalatok ka?
Jack: No, Ilocano ako
Jill: I thought all of you in Pangasinan speak Pangalatok.

The common knowledge of the people outside Pangasinan is that "Pangalatok" is a language. Jill thought that Pangasinenses speak only one language. They might often used "Pangalatok" as to the people but without derision or malice.

Which came first? I don't have any historical sources on the origin of the the word "pangalatok". But it is common sense to say that "pangalatok the language" existed first before somebody gives the meaning "pangalatok as ... tuktok". That means pangalatok is not coined from "Pangasinense sira toktok". With these statements, Pangalatok that refers to the people is neither offensive nor insulting nor derogatory at all though it is misused by many.

It is wiseful to tell that "... tuktok" is not the meaning of Pangalatok.What if we change it to "Pangasinenses magaganda buhok"?