I find it antagonistic on the OP's part to call this response "hostile": “we know it’s inaccessible, but we are not fixing it”. That's not hostile, it's honest. What more could you ask for than honesty?

If they had responded “we know it’s inaccessible, but we are not fixing it, because people with disabilities are a drain on society and should be put down”, that would be hostile.

Also: “it would be too hard,” (universally incorrect) is just not true. Unless his standard is "nothing is too hard for this noble cause."