Is it not correct to use 逗号 (punctuation) in a place where 顿号 should be used?
Technically, 顿号 should be used to punctuate for words enumerating. 

As we all text on computers today, it's more convenient to just type a comma, instead of 顿号. Most of time, it's acceptable nowadays unless some would nitpick. 

In theory, 顿号 would pause shorter than a comma.