"Before I ask, I need to offer some criticism to the members, and specifically, the owner of this site. Seems like all I see is negative replies to beginners asking questions. But maybe I’m new and naive and don’t understand how forums work."
Of all people, the owner of this site certainly doesn't deserve criticism. Not all replies to beginners are negative, so it's a bit unfair to characterize this site as having that feature. Sadly, what often happens is that some "beginners" are actually trolls who pose as beginners but who simply want to foment trouble and cause difficulty. So, when veteran members "take the bait" and respond, it can look like they're being unkind when, in fact, they're responding appropriately.
Still other beginners have the rather strange trait of asking a question and then, when they get a perfectly correct response, become argumentative and want to tell the responder why he or she is wrong! This, in particular, gets my goat.
"So my question is, why is the Ace considered a plus in the count?"
Short answer: it isn't; it's counted as a minus (negative) value.
"It can be counted as a high and low number."
Yes, it can. So, it has a dual nature, which is why, in many counts, the ace is counted as neutral, or zero. But, in all the other counts, it is counted as a high card (negative) because of its contribution to a natural (blackjack), where it counts as 11. The 3:2 bonus for a player blackjack is the most important player advantage in the game, and so it is more important to count the ace as a high card than a low one.
"If the casinos agree to hit on a soft 17, then they have an agenda."
Not sure what you mean by this. Can you clarify? If you mean that it is to their advantage to do so, then that's correct.
Hope this helps.
Don