Standing in Hindi is considered to be a state as opossed to a continuous action like in English. It's like the way we don't say "I am colding" in English, we just say "I am cold". Similarly we don't say मैं खड़ रहा हूँ in Hindi, we just say मैं खड़ा हूँ It's just the subtleties of the language that you have to memorize.
But that's a fact about Hindi rather than English. "We stand" in English might be a less common sentence than "We are standing" but one could say "We stand every day". So the question is, could हम (हर दिन) खडे हैं be a reasonable translation for English "We stand (every day")