Bill Zebub
“It’s probably Matt Mercer’s fault.”
But frankly, the DM just deciding that the PC cannot use their social skills they invested character creation resources in is not great. The GM gets to decide what happens, but it would not be cool if when you declare that you want to attack an enemy, the GM just declared that the enemy dodges without letting you to roll. The general assumption is the the players can use their PCs skills to get the things they want.
That comparison...between social skills and attack rolls...keeps coming up, but it's misleading.
First, the rules for the two things are very different. There are explicit, specific rules for action resolution and consequences for some situations, most notably (but not exclusively) combat. Then there are all the things that aren't covered by rules. Things that, dare I say, are largely what differentiate RPGs from non-RPGs, because they are what make possible the idea that you get to do anything you want...talking to bartenders, building a raft, burglarizing the keep....not just the specific scenarios described by rules. And there's one universal rule for all those situations. (Describe goal and approach, DM adjudicates, possibly asking for a roll.)
So, no, it would not be cool if the DM just decided that your attack missed, without an attack roll, if otherwise your attempt to attack met the parameters (range, vision, ability to act, etc.). But that's just an entirely different thing.
You may not like that the return on your "investment" in social skills is subject to DM whim, but it is. That's just a feature of the game.
(Also, for the most part wherever you "invested" those points would be subject to the same rule. Whatever skills you choose are subject to the same DM whim, with a few exceptions...i.e. the way Athletics/Acrobatics are used in Grappling. Your choice of Persuasion doesn't come at the cost of sword skill, or spell slots, for example.)