You are right that MLB owners make money even with little to no attendance, thanks to the TV and radio money. However, great attendance dramatically increases the teams' profit. You keep saying that attendance doesn't matter to owners, but it does. Simple math: 20,000 extra fans paying on average $35 per ticket for 81 games: 20,000 X $35 X 81 = $56.7 million dollars. Plus parking, concessions, souveneirs, etc.
I'm sure my numbers are low, lots of tickets are way more than $35. A lot more revenue is on the table. Not to mention higher TV ratings on Bally for a winner, which gives you a bump in TV revenue on the next contract, etc.
Also, to your "the fans will come back" comment... The Dolans went cheap in Cleveland a long time before the Castellinis did. Now they are in first place, going to win the division, and the fans are still staying away in droves. They had 6,000 for a Twins game last week, with first place ramifications. This is the same city that had sellouts for many years in a row in the 1990's. If you crap on the fans long enough, they won't be back.
I shared the Castellinis horrible winning percentages since 2015 on the prior page. Their clock is ticking. Stop being cheap a-holes, or sell the team.