One of the issues is using the word "engineer" for any of the brogrammer types. an engineer in any other proper engineering discipline does not become worthless with age, their experience actually counts for something.
Somehow we have confused people who stitch together software from pieces of "magic" that they do not understand with engineers.
The work I did in my 20s cannot even begin to compare with what I am doing today in my 30s. Those years of experience really makes a massive difference.
It is time people are honest about ageism and simply states the real reason they prefer fresh grad or 20-something brogrammers. It normally boils down to those people being willing to work longer hours for less money. At least in most of the cases of ageism that I have seen.