They aren't mutually exclusive either. It can be a fine line, but depends on the situation. I am not going to specifically speculate on Taysom vs Tanner (lots of factors there), but purely a principle of "We will be 'loyal' to our starter no matter how he performs" is probably not a culture we want to adopt. Purely that culture as a team can often set a standard of "once you earn a position, it's yours, so kick back and relax" type mentality. (NOT in any way saying that is what is happening here, but it CAN happen if over periods of time, if players know that "once a starter, always a starter" is the mentality and they never see performance based changes or evaluations). At the same time, you don't want a culture of "you get pulled at the slightest mistake", and a revolving door of pull/bench and put back, repeat, type thing. There can also be extenuating circumstances. Hence the fine line.

Few things drive elite work ethic and performance like a talented, hard working second-stringer or lower-line player that is right on your heels and working hard for YOUR starting spot.

Likewise, it encourages depth, because second-stringers or lower-line players know that if they work hard and put in the time and effort, they can earn higher spots and more PT. The best performers will play mentality has a lot of benefits.

If they do pull a starter for performance, or if a starter gets passed by a better performing player down the line, it does not mean that the coaches are disloyal. Help the guy that got pulled know what he needs to do to improve, and give him the resources to fix the issue. Let them put in the time to improve performance. Still show confidence in their abilities and build them up.

It all depends on the situation though - Tanner vs Taysom has certain dynamics that we as fans don't completely understand. But it comes down to coaches knowing their teams and players and making the best decisions. Loyalty is important, but the ways in which it is displayed isn't a hard fast rule when it comes to sports.