Sorry, but that is putting it simplistically. Some quick analogies would be to have the NBA go to one on one in overtime, when team defense got you to the overtime to begin with. Having Michael Jordan on your team would have been huge! The DH is a throughout the game item. Having different rules in overtime (3 on 3 in NHL), compared to the rest of the game, for the sake of ending it more quickly tends to favor certain teams. The teams are no longer equal. The rule change gives undue advantage to certain teams.
What's next? We can use metal bats in extra innings? Glove sizes can increase to allow outfielders from jumping over the fence? Pitchers can doctor balls in extra innings. So on and so on.
For over 100 years, MLB played extra innings the same way. Now, someone wants to change it. The DH rule came about for players like Orlando Cepeda who had no knees at the end. He could not play the field, even at 1B.
Finally, teams do not make money in extra innings. Most concessions are closed or closing by 7th inning. They really don't care to have it go 18 innings. Extra innings aside from stadium employee cost, also effects travel (air, hotel, bus, etc). Nope, this is strictly a cost saving move and isn't intended to be for "the good of the game". The DH was not a "cost saving" move and has no comparison to this purposed rule, other than it is a change.