EzekielRaiden
Follower of the Way
I mean, I can certainly agree that mistakes occurred. I don't necessarily think this is the one involved here.not including shields in EVERY light armor proficiency gained is a mistake by WotC.
I actually really like the idea that Warlocks can summon whatever weapon they like and use it (without Fighter-type features like masteries, of course--just the weapon and no more). It lets those Warlocks who choose to go whole hog for Blade Pact--which is extremely invocation-hungry, functionally being almost its own subclass all by itself--be interesting and flexible in a way other classes aren't. They're sort of the dark reflection of the Bard; where the Bard is mostly set in its ways and adds a flavor of something else to its full-caster suite, the Warlock is mostly set in what spells it can use, but verges on build-a-class with how flexible its features are.
And then if you really want those weapon masteries, just take a level or two of Fighter. You get heavier armor proficiency, shields, weapon masteries, Second Wind (another reason to Short Rest!), and if you take a second level, Action Surge for even more slicing-and-dicing. Coupled with the various sub-flavors from patron--Celestial as a healer, Fey as a trickster, Infernal for really dishing out the harm--it makes the Warlock by far the most mechanically-engaging class in 5e and a real breath of fresh air for folks like me who get so bored with the hypersimplicity mantra.