The community is ****, indeed, but that is why redlines must be put in place to reduce the amount of possible detrimental actions they can cause. Mass amounts of powerful spells lower the bar of magical roleplay and turns it into commonplace with many players that have little understanding of them, which will undoubtly cause troubles for the ST to police.
Being brittle is not much of a disadvantage, it just turns them into glass cannons and unless i missed something, nothing stops you from keeping them somewhere secure where they cant be directly hit. If you are in range of hitting the magegold then you can also hit the one holding the enchantment, which makes it redundant. Imho combative enchantments should be cappet at certain tier and have more downsides when using them; like temporal reduced strenght, fatigue, loss of mana, etc.
As a side comment; there are a few limitations present within the lore that are not reflected at the redlines.