Dalmatian croat accent

Why is it that the croats from dalmatia speak closer to montenegrins and serbs than croatians.

Istranci, Primorci, and northern Dalmatinci speak a pure dialect which is unaffected by the Communist and Royalist revisions of the last 150 years. Here are some examples of questions being asked:

ko je to muz ?, ki su ti muzi ?
ka je ta zena ?, ke su te zene ?

We also speak a chakovski dialect : ca hoces ?

Ona je radila celi zivot.
On je radil celi zivot.

Mi vavik jidemo mliko, sir, kruh, i sirov cesanj.