Agamon
Adventurer
Yes, but the fighter doesn't have it, while all wizards do. I was talking of the spirit of the rules and the general lore of D&D settings, taking also into account past editions (2e and 3e). With the current wording anyone can try the Arcane check, there are no trained only skills anymore.
Anyway the wording was different in the playtest, and we only have a preview now.
Arcana is just 1 of the 2 skills out of 5 possible that wizards can take, so not all of them are trained in Arcana. And yes, you can do this without training, but that's a pretty horrible idea, with not much better than a 50/50 chance to use a 1st level scroll, depending on Int.
But if you're a fighter than has the a Sage-type background and a high Intelligence, makes sense that he can read a scroll (which isn't casting the spell, but triggering the already cast spell, as I mentioned in the thread already). And even then, it's still not a great idea if the scroll is higher level.
And yeah, it might change for the DMG, but I think this was intentional and it's really a good way to handle it. The caster that can cast the spell should be the one to use the scroll, but anyone can try, if they're willing to take a risk.