What you have written here is so true and well thought out. I have, myself, felt like what you wrote here:

"I upvote and resteem your posts, but you do not upvote and resteem mine."

I have never written that and no one has ever written it to me but I'm sure that many of us have had those feelings.

As you said, how could anyone actually upvote or follow or interact with 10,000 people. It's just not possible even with 1,000.

My advice, which you don't really need: Just keep doing what your doing because your doing great! You always take the high road and that's such a great example!