People keep comparing it to things like gear, and getting Allagan weapons before others etc. but it's very different. In a year or two a Tidal Wave weapon or an Allagan/High Allagan weapon will be completely useless, so you're right, RNG on that isn't as much of a big deal. My point is in a year or two, not only will you still be able to ride around on your amazing EX mount, but (in the case of most people) if you are not fortunate enough to have gotten one, well, you're never going to.
Almost nobody on my server does Garuda/Titan/Ifrit EX anymore anyway, especially not farm parties. You have the odd group where five or six out of the eight need the clear and one or two people helping and wiping in desperate hopes of a mount. And now with them being removed as a requirement to move onto Levi/Thornmarch, literally no one will do them. If I knew I could get a guaranteed mount by doing fifty, one hundred runs, or whatever amount, at least it would give me a reason to still do it, a goal to work towards. But I could literally do hundreds of runs and not even see a mount drop. Or if I was somehow lucky enough to see one, I then have seven competitors rolling on it with me.
I understand that there are things that should be rare, special, and very difficult to obtain. But when it comes to the rest of the game, things are changed so everyone can enjoy it. Coil had lock outs removed, was nerfed, stuck on Duty Finder, and given the echo buff for those who wouldn't have been able to do it otherwise. Well some people care about things like vanity mounts just as much, if not more, than progression. I just think it's a real shame that they go the effort of designing these amazing things only to ensure that the absolute smallest percentage of users will ever get to attain it.