Honestly this is a tough Question for someone who's a Jeff Jarrett fan, such as myself. On one hand I'd say without question, no, because everyone deserves a shot at becoming a Main Eventer and Jarrett proved to be capable of hanging with some top names in the business.
However, on the other hand, I'd say Yes, because even when I use Jarrett through most storylines "I" create in games, or in my head - I use him as an upper-Mid Carder, Lower-level Main Eventer. (in cases of which the Main Event would need 3 or more individuals.)
You see, the problem I believe a lot of people are running into is the fact that by the time Jeff Jarrett finally got his big break in W.C.W, for whatever the reason may have been, most of the Main Event level talent was either on their way off the sinking ship, or being jobbed out to lesser known/named talent, that when they lost to Jarrett.. it didn't mean anything, anymore.
You add onto this, the fact that Hulk Hogan, arguably the biggest name and icon in Professional Wrestling blatantly and bluntly refused to lay down for Jeff Jarrett on a Pay per view card - because, and to slightly quote Hogan "He wasn't anywhere near Hogan's league". That was a huge pile of dirt thrown on the "Grave" that would later be known as Jarrett's Main Event career.
Jarrett holds victories over such names like; Edge, Shawn Michaels, Kurt Angle, Sting, D.D.P, Scott Steiner, Booker T, Kevin Nash, Ric Flair, Chris Benoit, and several other top named talents. Yet once again, depending on when he defeated those individuals.. they were either still mid-card themselves, in the same position Jarrett was trying to become Main Eventers, or Main Eventers that were on their way out merely putting over other talent for the sake of doing it.
Through my eyes, Jeff Jarrett could hang with anyone, but his matches weren't what I'd consider "Main Event" exciting. By that, I mean he's more of a technical type of athlete, with no overly huge amount of charisma, or pzazz behind him. In fact, if it wasn't for Vince Russo & Eric Bischoff backing him in W.C.W through storylines (or behind the stage, real life issues) then Jarrett likely would've never became a Main Event talent in any Company.
On that note, if he'd have went on to create T.N.A, and tried putting himself over as the Main Event talent.. he'd have failed worse, just because people would've been smart enough to realize no other Company that he didn't have creative control over took the chance of pushing him.. so he's only in that spot in T.N.A, because he's pushing himself and that'd look selfish and careless for business.
So, on those notes.. Yes, to me Jeff Jarrett has some of the qualities to be a Main Eventer and he can hang with most of those we have today. (Shawn Michaels, Edge, Sting, Angle, etc, etc, etc) However for the most part.. he's got more Mid-Card "blood" in him, than he does Main Event material. (not enough to carry the Main Event, anyways - but similar to Jericho, enough to support one by way of multiple men involved)