Yes, that is the reality in regard to master's runners. Not only do people generally not care about these "old guys," but no one really understands the affect of age upon performance. Sure, there will always be exceptions with accomplished professionals, such as Meb and Castille (and perhaps that is part of the problem, so to speak?), but to compete at the highest level at 40+ is so difficult it is virtually imaginary.
As a 47 year-old runner, I am nowhere near the OP's ability, much less the very high level of performance required by the race he mentions. I do think his words were somewhat antagonistic, though, and he should be thankful for being in the "realm of possibility" for a comp. For me, that would put a huge smile on my face. He is probably in the top 0.5% (or better?) for all runners, and he is 40 years old. Virtually no one else knows what that means, but we "old guy" runners do. Be happy and enjoy your excellent performance.