Now tell me what cow experience do you base that observation on? Do you actually have any first hand information that backs up that claim? I am pretty sure you have none! But... easy to make such a comment, based on utter ignorance and arrogance!
Yes, it is not easy to find a job after 40, impossible? Hmmm not sure..., yes will be very hard, and if you can accept that it might never happen before you start the training, at least you know what you are going to!
I am over 40, when I did my initial TR, I was not slower, I was not dumber, I actually know of younger guys, who was much less focused needing extra sim time sessions!
Well, as a flying instructor it is my first hand experience that people over 40, and certainly approaching 50 are generally slower to learn the fundamental skills required to learn to fly, taking up to 20 hours longer than a young buck. This is fine at PPL, CPL and even IR level, but on a type rating an employer is unlikely to want to pay out for extra sessions.
Yes, there are exceptions to the rule, but in general younger guys are quick to pick up the actual physical act of flying the aircraft, but perhaps struggle with the more in depth stuff like navigation. For older guys the opposite is true, slower to get to grips with flying the machine, but once they have it's much easier to teach them complicated procedures.
So for your typical guy, I would say if you're over 40, I'd have to think long and hard about leaving an established career to chase this dream. I'm not saying there aren't exceptions, and perhaps you yourself are used to operating other pieces of machinery, or have some other engineering background which assisted in the way you learned to fly, but for most over 40 they just take that bit longer and an employer may not want to pay for the extra training, however good the end result will be.
The only people to ever fail the initial type rating in the history of the company I now work for were in their late 40s/early 50s.