I don't agree at all. It's easy to say that moderators/staff in general should be on at least once a day for a little while if you're younger, which in this case you are. The reality is that people can't always get on every day or even every other day, and that is fine. Expecting people to get on once a day is too demanding as a gmod server and will only serve to push those people out of their staffing positions. They are also far more likely to get burnt out if they do play that frequently, which will inevitably end up in resignations or time off from the server - something that I'm sure someone like you wouldn't appreciate.
You need to have patience with other people and realize that just because they're not always going to be able to get on right when you need them, doesn't mean they don't care. They do what they can when they can and within reason. That means that, even if they ARE otherwise available to get on, that doesn't mean they should be expected or forced to do so. This also ties into my next point, which is this isn't a job. Nobody is getting paid for this, which for some people, means it automatically takes a back seat to their education and employment irl. You really should put that into perspective when you say the things you do and give criticism how you do.
Finally, you should probably stop writing a paragraph response to every -1 or -/+. I get you want to clarify stuff to people who may have misunderstood, but at this point in the application, it's simply coming off as "Unclear can't take criticism or feedback very well". You're young, and as such you have a bit of learning to do for this role. If you can improve on everything people are saying to you in this application instead of refuting and writing it off, you'll do far better in the long run.