In an ideal situation, your Captain should be creating the part of an owners life that has everything to do with his or her yacht. This includes it's location, it's upkeep, it's maintenance, the environment on board, the reporting in the various areas (i.e. accounting), the people who help bring the yacht to life, the experience the owner has while on board, etc. This is a large responsibility and it comes down to a lot more than just managing the credit card, hiring the crew and moving the boat.
The difficult thing to see as crew, sometimes, is all of these things at the same time, and how they are intertwined. Over-spending can cause hours on the phone with the accounting department where maintenance, if new on board and maintenance was not performed well in the past, can create a large headache for the Captain where they must find qualified contractors, competent crew, have discussion on budgets, etc. all while keeping up with the day-to-day items and keeping trips on schedule.
As crew, sometimes we are narrow-sighted and only see our, or a small portion of, another particular department, mistakes that happen and perhaps feel the need to point them out on demand. It's SUPER important to remember there is a longer-term goal, and being short-sighted can add stress and aggravation to the day-to-day work of another head of department. Even small comments about why someone would do something a certain way might be short-sighted in that we don't know everything that came in to play about a particular decision made. Maybe step back, watch and possibly learn. If it still doesn't make sense, try asking before simply commenting or worse, blaming.
Remember what we see is also often seen by others. And sometimes, change is difficult and can take a little time to implement. If we've asked, it still doesn't make sense and nothing is changing after several months, you can ask your superior. But jumping the gun and making assumptions and jumping over people's heads can get you in hot water. Stay away from that syndrome that somehow makes you feel you could do things better than your superior. If you feel this way, either you need to move on (in that perhaps your superior is actually incompetent) or take a step back and learn to trust your superior. Maybe they have been right all along and you could learn a thing or two, regardless of their approach... just be aware, your superior likely has a certain knowledge you don't yet possess and perhaps you should try to trust the process. Life in general, as well as yachting, is a process best experienced with patience :)