I'm not "young" anymore and not "old" yet, but I'm quite saddened by this point of view: 'The young understand new technologies better than the old do, and are like a clean slate: they will rapidly learn the latest coding methods and techniques, and they don’t carry any “technology baggage”'. Software business seems mostly about exploitation of the naivety of the youngsters and less about software and programming.
I'm definitely old - going on 40 this year - and I don't recognize myself in that argument either. I think the reason why these points sound like they're made up is because they are, in fact, made up to justify something that's already been decided based on feeling.
Age discrimination isn't about competence (programmers peak much later than 40) but control. It exists because the VC man-child oligarchy (oddly enough, software inherits the age-discrimination culture from business-culture colonists who'd be "too old" to write code) thinks that people will work harder if this shitty, artificial time pressure is put on them. And, of course, much of the ageism and sexism is unintentional but still exclusionary. See: open-plan offices and the aggressive micromanagement of Scrum. I don't think Scrum and open-plan were devised with ageism in mind, but they contribute massively to the attrition. As people get older, they have less tolerance for macho-subordinate bullshit.
This macho-subordinate culture that is imposed on software engineers needs to die. It drives out an incredible amount of talent, makes us an HR nightmare as far as diversity goes, and it has nothing to do with programming; in fact, it detracts from the quality of what is produced. We have to kill it at any cost and professionalize our industry because we can't trust our financial backers.