First law of holes: if you’re in one, stop digging.
Nobody (well, nobody with an opinion worth speaking of) thinks defaulting on the debt is a good idea. Construing opposition as “default deniers” is harmful rhetoric, not conducive to fixing a severe problem. The “government shutdowns” always have the caveat of not stopping spending on “essential services” - which raises the question of why those non-essential services are funded at all.
That there is a “debt limit” is not to just a subjective artificial cap on spending, it’s to recognize that it’s an objective point where bad things happen. Removing the limit does not change the economic reality that increasing debt beyond that point becomes exponentially harder (starting from the current “d@mn near impossible”) to reduce that debt ever short of devastating economic consequences.
When driving headlong into a wall, you can either slam on the brakes or slam into the wall. Object that slamming on the brakes will prove very uncomfortable to the occupants (pressing against seat belts, near-whiplash, stuff thrown around, squealing tires, etc) does not justify failing to mitigate/prevent a full-on crash.
Problem is, so long as tax revenue comes in and debt service payments are made, no harm is done and few are concerned. The kids joyriding the convertible continue to ignore the parents screaming at them to stop before someone gets killed. And yes, if we default on debt service payments, people will get killed.
I think the country passed that "Bridge Out Ahead" sign several years ago.