In sports, and also a lot in in general life, but particularly in sports, quality often suffers in favor of profit. For example, take baseball. Baseball used to dominate interest. Now, as looks become more fractured, individuals and teams will stop at very little to maintain some, at least a modicum, of interest. The team's grip on to what already exists ever so tightly, as viewership slowly slips through fingers, because even a small amount of attention equals a large amount of funding.
Few individual fans will affiliate beyond one particular team. Commitment to the larger league as a whole requires an amount of time and patience not at all common. But, TV stations and team owners will never sacrifice profits by reducing the length and number of games and to, as a result, make the quality higher for the fan. The MLB, NBA, and even NFL seasons are already long, maybe too long (especially MLB). But a game and a season translates into SO much already accounted for programing that contracts are worth a small fortune to a TV station and therefore a fortune to the team owners. As long as the bottom line remains the primary concern for owners they will never choose to voluntarily lessen it.
Therefore, as a follower of a franchise, since the owners usually care the utmost about the pocketbook, the best was to harness the owner’s attention is to attack the pocketbook.
The fans provide, in one way or another, money to the teams. That means they can reinforce positive behavior by encouraging it with a reward. Likewise they can punish poor behavior by withholding the reward. In either case the ultimate power rests with the collective actions of those providing the funds, of the fans.
I don’t know the exact best course of action to suggest. While long games, seasons extending deeper and deeper, and increasingly particularized media markets may equal short term increased profit (like the housing bubble did), in the long term it means a lot less desirable and less palatable product (also like the housing bubble).
It seems the only option left to a sport's fan to really exercise any influence immediately, and really the most effective influence at all, before the sport escalates to the point of unfollowability (I made up that word!), is to deny funds. That speaks the loudest to the owners. If the league sees fans reacting negatively to avariced attempts then hopefully it responds accordingly. What else can the fans hope to do? In the end, the best way to support a team in the long term might be to cease supporting them right now.