In just one year you have learn't a lot. So now get N+1 in an MTB and learn how to bounce.

Every thing you say is right but some may not agree.


Edit
I started on mountain biking and only went road 4 years ago. But I still occasionally get out on the MTB. I know it is a different discipline but Mountain biking is not easy. Once you master staying upright- the fitness required is different. I do XC and that is on the South Downs. A ridge that runs for 100 miles and a max of 800 ft climbing in one spell in our region. But those mile long climbs at 12 to 15% give you a work out that cannot be done on road bikes unless you climb a mountain. That is about the nearest I can put it to- the clue is in the name---Mountain biking-- but the fitness you get in climbing those hills is unbelievable. Get to the top of a hill with lungs bursting and quads screaming and you soon learn how unfit you are



So don't give up on mountain biking- Just look at it as cross training for the few slopes you get on the road