Not quite correct, but close...if you check around on the sites, there are quite a few pro musicians using Tyros2/3/4/5, including myself and several SZ members.
In fact, some pros and advanced players are using mid-line arrangers from various other brands as well as Yamaha.
Mind you, we are using those things because there's nothing BETTER currently offered... But it isn't always a perfect fit. A pro is probably a bit more concerned with size and weight than most home players, and is usually a bit more concerned with in depth editing than most home players. On the whole, I'd say that only Korg offer a REAL 'pro' keyboard arranger, with virtually as much editing capabilities as a WS (the usual tool of choice for most pro players).
But there's still a boatload of stuff the pro player gets with a WS that's missing from most arrangers, including arpeggiators and multitrack audio recording, full synth capabilities with a ton of knobs, loopers and the like.
The two ARE converging, to a degree, but not fast enough for me..!