Is it really that hard to produce an opposite-handed version? That sounds more like a convenient excuse.

Surprisingly. A lot of eg: aircon ducting, placement of stuff in the bonnet, dash configuration, wiring looms, is all -handed. Certainly doable but it’s a significant burden in both design effort and handling of parts/supply chain/inventory which may or may not justify it.

I briefly worked on doing LHD-to-RHD car conversions and the devil was definitely in the detail.