Most, seemingly, disrespectful and pushy horses are not that way at all, they are simply doing what we have taught or encouraged them to do through not understanding basic equine behaviour.
Horses understand and respect each other’s space they only push on each other to establish dominance, who is going to eat or drink first. Once they have an understanding they enforce that from time to time by making couched threats, turning their head or pinning their ears is usually enough.
People can, and do, confuse the heck out of horses, sometimes we call them over to us for cuddles and carrots, then we drive them away so they don’t crowd us at the gate. Other times we might step backwards, inadvertently inviting them to approach us, while lunging and so on.
When the horse understands what is expected of him and where his place is in the pecking order of the herd he will be much happier and a whole lot less pushy – unless of course we have elevated his status to a higher position than our own.