Why do yungsters and new riders want full suspnsion this, disc brake that.
Despite me being a retrobiker - because they work better and allow people to ride faster and longer.
My two mountain bikes are a fully rigid one and a hardtail - and I love riding both of them. But I can't keep up with my b-in-law on his Trek Fuel EX8 - he can out-brake me, out turn me and he can ride through stuff flat out that I have to pick my way through. If we swap bikes the situation is reversed.
His bike is also more comfortable and so he can ride it longer than I can ride mine before feeling that someone's been kicking my arse all day.
The trade-off is feel - his bike feels uninvolving and 'dead' - it has no soul. How happy I'd be with that trade-off depends on whether it's a 4 hour ride or a 14 hour ride.
My bike only wins on smoother terrain or uphill.