You weren't all that explicit, and GP responded to your comment as written. There really is no call for being this rude just because you think you were misunderstood.
2. Rude? The person who replied did what was said. The first sentence implied that my point was indeed correct. Then the second sentence just ignored what the first sentence implied and ignored the point. They seemed to think the problem is a long-standing problem that banks have. Instead of a problem that has been growing for years because the supply of people who know the tech stack is decreasing. It's fair to point out to people you don't think they understand the problem.
3. Misunderstood? I believe they implied in their first sentence I was correct and that they understood the point. They just didn't like the point.