This being an assessment based on local awareness of circumstances.
Risk. Reward. Administrative cost.
The first of these I blocked when I looked at the domain and realised that the TLD were registering any old line noise. I'm not going to bother sorting that. Search for other experience turned up Blue Coat.
I subscribe to blocklists, and they update periodically. There are other levels of protection.
When a TLD is 99.9% malware or scams, it's far easier to block it outright. Registrars should take responsibility for what they're registering. Not my problem.