Love this kind of progression towards a mount. Gives me a reason to log into wow and enjoy it. I wish there were significantly more Mounts that were obtained this way. Maybe through a daily puzzle or a daily lore npc. These idea's are guaranteed reward from consistent work and very rewarding. From a self progression irl stand point things like this are what makes world of Warcraft such an awesome game full of adventure.
Rather than a total collection achivement for mounts, I'd like to see an expansion achievement for mounts.So obtain 100 Classic MountsObain 50 TBC Mounts (Reward - a cool TBC mount)Obtain 75 Shadowlands Mounts (Reward - a cool Shadowlands mount)etc. etc.That would be a lot more fun and interesting, and wouldn't be so offputting to newer players who are hit with COLLECT FIVE HUNDRED MOUNTS! ;)