I'd suggest that you're missing the bigger picture of what they do, but again, I've never used them... just answering specifically what the OP asked.
I'd say we probably agree on quite a few things... even if the degree of non-musical effort required isn't one of them.
I agree there's a problem on display here. It's not necessarily anything about musical quality. Musical talent and business acumen aren't even related. Some of the best musicians I've met could barely tie their shoes, let alone manage their enterprise. Musicians sometimes tend to be introverts too, who can dread the very thought of SOCIAL media.
I agree that the question itself here doesn't bode well for future prospects. Personally, I would estimate a much higher chance of success for someone who was asking something like "Can anyone suggest some resources, or people I can partner with so I can learn how to market my music and effectively manage the fans I pick up along the way?"
Might seem like a subtle difference, but attitude is everything. The days of a musician phoning it in every few years while someone else takes care of everything are gone if they ever truly existed. The major label acts I've known were constantly having to do things that had nothing to do with music. The good and bad news is that there was always some photo shoot, interview, signing, etc. Between that and the tour schedules, I never did understand how they ever got around to actually recording anything.
Major labels these days are looking for people who are tuned in and actively working their networks. More and more, they're looking for people who are already doing it, not those they have to teach. We live in an era where Trey Songz is pulling in half a million annually from his app, and rappers are getting 7 figure deals based solely on their subscriber count.
Independents today? Forget it. SOMEONE on their team has to know what they're doing, and we don't all have a Sharon Osbourne in the family. It's not necessarily all about social media or any one thing, but anyone who DOESN'T understand those things owes it to their career to find someone who does.
To be realistic: It's not hiring a PR
firm vs having everything done perfectly that's being discussed here... it's hiring a PR
firm vs. nothing getting done.