Fractional Captain reported after departure the flight was cleared to a fix that was verbally difficult to understand from the Controller who reprimanded the pilots when they asked for clarification. Reporter stated they previously have had similar communication difficulties with this facility.

Narrative

After we departed DAL we were at 7;000 ft. being vectored on a departure (KUSSO 1 Departure) . Departure frequency 118.55. We were given a clearance to go direct to (unintelligible); we asked a second time. Still unintelligible. After a third time we requested specificity and were reprimanded for asking. We asked spelling clarification of the intersection to be clear. We explained to the controller it was not clear what he was saying. He again explained to us that we need to figure it out and go to it." We finally understood the clearance then to be direct to ZERLU intersection. So we proceeded direct at that point. I have had repeated issues with DAL Approach not articulating; speaking too fast; rude tones and unprofessional attitude when asked to repeat due to not being able to understand what is being said. When I have to file reports because I misunderstood a clearance; I assumed and didn't verify in the past; and now when I ask them to verify because they are not speaking clearly and too fast; I am put into a position where safety is jeopardized because ATC doesn't want to repeat and they are not following the CFR's. This is clearly a Fail/Fail scenario that jeopardizes safety. If I assume the incorrect waypoint and an accident incurs afterwards; whose fault is it? Obviously mine. Why? Because I did not clarify. So why am I getting reprimanded from ATC for being safe? This is clearly beyond unprofessional attitude on the radio and is unsafe and in violation of CFR's. Pilot's should be able [to] request clarification at any point and time that a clearance is not understood or is unclear or unintelligible. Speed talking is only as good as it is understood. When safety is compromised; speak slowly; clearly & articulately. Being told to "figure it out…."? How insulting! How safe is that? I could say offensive things over the radio but choose not to; so is that what we are allowing now? This is happening a lot more often; specifically with DAL Approach. I value my professionalism and my personal safety over any controllers pride."