Did you ever think that maybe, just maybe those people who tried to explain ragequit after you pulled because they perceived your pulling as ungrateful and insensitive to new players who wanted to hear what they had to say? Did you ever think that they might be so annoyed by your unwillingness to wait a minute for an explanation that has a chance at saving a wipe, that they don't want to run with you? Did you ever think they might see a WHM who pulled as immature and not willing to coordinate and work with them or anyone else?
I never see people who explain quit after a wipe unless someone pulled mid-explanation.
At that point, they aren't the problem; people who do as you do are.
It is not impatient to explain a fight, it is helping the group succeed. No one likes to wipe, and no one likes to wipe repeatedly. If through someone's explanation, the amount of wipes a group experiences in content can be lessened, then that explanation has value to the whole group. People who explain fights in long-winded form often do not do so because they want to show off their knowledge of the fight; they do so because good explanations are proven to help groups succeed more, and more often.
Often if it's a mechanics-heavy fight (like The Chrysalis), if someone comes in and says "first time," and says they haven't even watched a video but want an explanation, I'll groan, but take the 45 seconds it takes to explain the fight so they have some idea what to do. And usually, we succeed in one or two attempts.
I'm sure there are jerks on both sides, but if someone is explaining, it is extremely rude and inconsiderate to interrupt them or not let them finish.