I think you're wrong, but I applaud you for being more open-minded about this than most Democrats.
These situations aren't analogous. These NFL players are at work. You could argue that they get paid millions of dollars to be patriotic. I'm not saying that's the case, but you can make that argument. Therefore Trump is not saying they should get fired for their speech, but for not doing their jobs. You can even make the argument that it's good business advice. Their target audience are patriotic people, so it doesn't really make sense to antagonize those people from a business perspective. Additionally, some people aren't even saying that they should be fired, just that they will no longer be watching the NFL. That's definitely their right as a consumer.
An analogous scenario would be Trump saying they should lose their jobs for participating in a BLM rally outside of work. That's never gonna happen in a million years.
With the Charlottesville rally you also have people saying they shouldn't have even been allowed to have their rally, or justifying violence against these people. That's a whole different universe.
Also, the people that lost their jobs because of the Charlottesville rally were not millionaires. They are much more dependent on their income than these NFL players.
Players at work - This argument is a red herring, unless you're arguing that NFL players have a contractual obligation to stand for the anthem, which they don't, as I've already explained above. The only other justification for this argument is a belief that you don't have Constitutional rights anymore when you get to your workplace. Is that your position? If it is, you are incorrect. You always have your Constitutional rights, regardless of whether you are at work or not.
Patriotic- You could make that argument but its not a strong argument, and I think the fact that you opened the argument with the disclaimer "I'm not saying that's the case, but..." seems to be a red flag that you already know how weak of an argument it is. They absolutely do not "get paid millions of dollars to be patriotic". They get paid to play football. The owners pay them handsomely to do their job and don't hesitate to drop them like hot potatoes when they don't do their job. If being patriotic was part of the job and they weren't doing it, the owners would get rid of them. You might subjectively
wish that being patriotic was part of their job, but that isn't the same as it actually being their job.
Business advice - Trump tried to become an NFL owner
and failed, he also committed a string of poor business decisions that ultimately ran the debacle football league known as the USFL into the ground, including wild overspending and his disastrous business advice to compete directly with the NFL to force a merger. NFL owners aren't going to take advice from him on how to run their teams. He's demonstrably not qualified to give such advice
as he was an utter failure in terms of managing football teams.
Target audience - I assure you that the NFL's target audience is
everybody not just "patriotic people". There is a game this Sunday at 9:30 EST. Do you know where its being played? London. What was your point again?
As for the rest... Consumers' rights aren't relevant to why conservatives choose to defend Kluxers free speech but not the NFL players. Also, saying that the players shouldn't
be allowed to protest has many similarities with saying the Kluxers shouldn't be allowed to protest, and the fact that you are doublethinking that kinda proves my point. Finally, whether a millionaire is more dependent on their income than a homeless person doesn't remotely explain why conservatives defend Kluxer's free speech but not NFL players, unless your position is that only poor people have Constitutional rights.