Depends. Generally secession is associated with bitterness and anger -- taking back one's "rights" from the "oppressor."
Secession isn't usually attempted in a calm and peaceable spirit of respect for the country one's leaving. Consequently it's no surprise that secession attempts are met with anger and resentment from those who are cast in the role of the "oppressor" in some narcissistic drama.
When separatist movements take a more peaceful route and ask for consent from the rest of the country and don't regard their fellow countrymen as evil oppressors they may meet with more respect and consideration from the other side.
LOL!
Having to ask permission to leave a voluntary association would negate the entire concept of sovereignty.