Dallas knows that it has to eat travel costs, and probably accepts that. What it can't accept is a vast number of its games starting at 9 or 9:30 pm because they are being played on the west coast.
The East is all on the same time zone, and thus there is the luxury of aligning the division geographically (well, if you move Nashville, they are in the Central time zone).
What Dallas, and perhaps others in the west, would like to see is time zone-based divisions (Pacific, Mountain and Central) so that the respective fan bases can watch divisional games that start at 7pm-7:30, particularly important in those the markets that are trying to nurture a new fan base.
If the Pens moved to Houston, or even Vegas...
Western Conference
Pacific Division
Vancouver, San Jose, Los Angeles, Anaheim, Phoenix
'Mountain' Division (NW)
Calgary, Colorado, Edmonton, Dallas, Houston/Vegas
Central Division
Chicago, Columbus, Detroit, Minnesota, St. Louis
Eastern Conference
Northeast Division
Boston, Buffalo, Montreal, Ottawa, Toronto
Southeast Division
Atlanta, Carolina, Florida, Nashville, Tampa Bay
Atlantic Division
New Jersey, NY Islanders, NY Rangers, Philadelphia, Washington
You would still have some teams that are one time zone off from the rest of their divisional rivals, but at least you'd be rid of teams TWO times zones away. Dallas does have a valid point here: Being two time zones away from divisional opponents is brutal.