The argument isn't really Bulls vs Dubs. It's quite possible that the Bulls would beat the Warriors in a 7 game series, they did after all have the greatest player of all time. I think we're going to eventually look at Steph as the greatest shooter of all time, but certainly a lot has to be proven before that claim can be made.
The original argument was that the Warriors should have an asterisk by the record if they were to break it because the league isn't as good as it was in 1996. The Lakers, Celtics and Pistons were all cited as better teams that the Bulls had to beat than the teams in the league right now. Well the Pistons won 46 games that year, the Celtics won 33 and the Lakers won 53. Certainly no world beaters. There were 4 teams that won at least 59 games (Bulls, Magic, Sonics, Spurs) whereas this season will likely only see 3 teams hit that mark (and the Cavs have to finish 4-1 to reach 59). You could make an argument for a more competitive league if less teams are winning around 60 games.
There were 18 teams that finished above or around .500 in 1996 and there are 19 teams that will finish above or around that mark this season. The current 76ers and Lakers would have been 2 of the 3 worst teams in the league in 1996. So maybe more bottom feeders but slightly more average to above average teams.
There were 4 different MVPs in the 6 seasons before 96 (including 2 years where the best player on the planet MJ did not play either at all or for a full season) and there have been 4 different MVPs in the 6 seasons preceding the current one. Very difficult to say which league had more talent especially as the argument could be made that the best player in the league does not play for the Warriors (LBJ). No such argument could have been made in 1996.
The big difference for me is when franchises were founded. The last NBA franchise to be founded currently is the Pelicans who were founded in the 2002-2003 season. In the 13 years before 1996, a total of 6 teams were started from scratch. There were significantly less well established teams than there are today.
None of this mentions analytics and other data more available today, giving opponents plenty of information on how to beat teams. You could also say that more tanking occurs in the current league but that's more speculative.
So all in all it was tough for the Bulls to win 72 in 96, and it's been tough for the Dubs to win 69 this year. If they break the record they should be celebrated as the greatest regular season team in history.