How do you want to define the “professional video world?”
How geographically constrained do you want the survey to be?
What type of editing are you interested in?
And what type of editor?
Once upon a time (not that long ago) - a “professional editor” had to work for a relatively big enterprise - because very few individuals could afford the gear and infastructure to effectively edit. Only film studios or TV stations had the financial clout to play.
Today a hundred times the raw editing capability costs a hundredth the price - and most modern laptops can run capability rings around the state-of-the-art Hollywood tools of one or two generation ago.
For my money - many older editors (not all, but many) who came up in the celluloid or TV era are generally most comfortable with Premiere Pro since it’s based around the traditional track-based paradigm that has ruled the industry for 50 years. PPro doesn’t require editors to alter their workflows or thinking too much. It’s an evolutionary approach, largely. A good chunk of the commercial shop based pro editing industry, highly values that.
FCP X was basically created to challenge those traditions in search of greater editing efficiency - generally through new forms of metadata leverage and rethinking basic timeline behaviors. It’s more a revolutionary, than evolutionary approach. It’s adherants tend to be editors willing to tolerate greater change in a search for what many of us see as greater efficiency. (I’m one of those types, myself so I’m definitely biased toward that view!)
X has sold more seats globally than Premiere Pro -. but in many US edit shops - Premiere is far more common as experienced editors chose to stick with editing approaches they had more experience with and migrated to Premiere after Apple dumped and moved on from traditional fixed track-based editing.
Basically, if you want a gig in a traditional shop holding down a “seat” - PPro is still probably the smarter play.
If you are more interested in new media, forms like documentary where the database and search structures of X really shines - or learning a personal expression through video tool you can buy once and own forever, the arguably richer cohesive metadata focus of X is likely to force you into studying that more - via its tagging and internal search system - and turn out to be a stronger play for the future.
Both are fine tools and either will let you explore the actual central skill of editing. Sequencing audio and visual ideas in order to attract and satisfy an audience.
My 2 cents. Others will likely see it differently.
I largely agree with Bill's assessment. It really boils down to two factors: geographic location and whether or not you need to collaborate with others, who will also touch the edit project. If you are in NYC or LA and need to work collaboratively - or pass your material on to someone else - then odds are, it will be Premiere or Avid. The rest of the country is a toss-up. There also seems to be a bit more use of FCPX professionally (at facilities) outside of the US than inside. I know a lot of editors who use FCPX some personally, but do their client work in Premiere for best interchange.
All of the big shops that I'm aware of in my State are on Premiere. All of the freelancers I know are on Premiere except for 1. But he used both FCP X and Premiere. I use Premiere because I spend a lot of time in After Effects and they round-trip nicely.