Austinfan touched on what would be my reply about Fetterman. He exudes the "common touch," working class persona that comes from his personal background. But underneath that, he's a fairly sophisticated policy wonk. You don't get admitted to the Kennedy School's masters' program, much less survive the two-year program, without real abilities.
Fetterman is plain-spoken in his public appearances, which, IMHO, will likely appeal to a fairly broad spectrum of Pennsylvanians. He won the Lieutenant Governor's race...three years ago now, despite not being anointed up-front by the state party.
But in a private setting? In a meeting with business executives? Fetterman has the background - both his formal education and his executive experience, in Braddock and Harrisburg, to connect with these people, if he chooses to... and that (again, IMHO) is without exploiting his Kennedy School network connections. If he does choose to take advantage of that network... then you're looking at a large conference room with PA executives meeting Fetterman...and a half-dozen highly influential JFK alums who endorse him.
Now, I'm not a "business professional, college educated in PA," as MJS identified as a possible challenge for Fetterman. I'm a retired public servant - with a BA from Penn State (!), but with an out-of-state MPA. So I'm not quite in the group MJS noted. But I am an "older guy," and as you undoubtedly know, I lean toward fairly traditional views on public behavior/language/dignity etc. (I've gotten into some trouble because of that?)
But you have to look under the hood. Fetteman's style isn't one I would adopt, except for the blunt honesty, of which we have far too little in American public political life. But when I look under the hood, I see a fairly sophisticated policy thinker, who isn't even a little bit afraid to challenge "conventional wisdom" that isn't consistent with reality. I like that.
So... the style, the surface should appeal to PA's working class. The blunt honesty as well. Will those put off "business professionals"? I guess it depends, in my mind, on who we're talking about. Corporate leaders, who know how to see through a surface veneer, and whose rise has depended on being able to do that, to evaluate substance rather than style? I think they'll figure Fetterman out; whether they will agree with his real policy stances is a different question (and germane to his garnering support from that sector).
The typical small businessman, who may have a BS in finance or management or some such, from PSU, or a similar degree from a PA state university? Well, I don't know; small businessmen with... how to put this... relative constrained higher education experiences?... may or may not have the tools to see beyond the surface style. That will depend on their real-life experiences, because their university years (based on my somewhat limited first-hand knowledge of the business curriculum at PSU 40 years ago!) will not necessarily have exposed them to much understanding of the world of ideas outside their majors, nor equipped them to understand (or care about) broad policy concerns. On the other hand, I'm not sure it matters; small businessmen of this kind seem to tend to vote Republican pretty much regardless. To put it in (simplistic) economic terms, these folks tend to get the micro stuff - they understand what impacts them and their firms; but the macro stuff is esoteric and not particularly relevant or interesting - but it's the macro stuff that drives the impact of public policy... and they often don't get it.