Even judged by the average royal family member, this person must be quite the arsehole:

Laurent received €388,000 (£333,000) last year from state coffers and lives in his home rent-free. “This is not about financial means but principle,” he told Belgian broadcaster RTBF. “When a migrant comes here, he registers, he has a right to it. I may be a migrant too, but one whose family established the state in place,” he added.

WTF?!

Talking about deeper motivations, I suspect this made him throw a hissy fit:

In 2018, his annual state allowance was cut by 15% for a year because he met foreign dignitaries without the federal government’s approval.

Reading more of the article he says a few things that seem to make sense on the surface:

Laurent and his British wife, Claire, have three children now in their 20s. He pointed to medical costs and his concerns over his family’s financial well-being, since the royal allowance will be cut when he dies.

- until you consider that he does get 32 000 euro per month.

I’m glad to hear that Belgium treats its royalty like normal people.