Companies settle all the time. It's common for insurance claims, for example. At a not-for-profit organization I'm involved with, a homeless person punched someone on the sidewalk outside their property. The victim then turned around and sued the organization, who had nothing to do with the incident except that it technically happened on their property (which is in an urban area). The president of the organization wanted to fight the case in court (on principle, because he felt that he shouldn't be liable, though he did express sympathy to the victim). The not-for-profit's insurance company wanted none of it and they settled for something like 50K. I'm sure that the insurance company has better lawyers than your average joe, but I'm also sure that they run the numbers and look at the risks (financial and reputational) and then make a decision whether to fight a case in court or not.
a) to be fair, this homeless person punched them in the face
b) the organization does medical research, not work with the homeless. It just happens to be that the victim was walking on their property when a homeless person who was also passing by punched them in the face. The victim was indeed hurt and needed to go to the hospital. But the president of the organization felt that someone getting punched on the sidewalk (which is in an urban area... we're not talking a large property) was unfortunate, but not something his org should be responsible for. However, the insurance company didn't want to deal with the lawsuit, so they settled.
Sure, but if you get a judge that decides that the penalty should be salary from the time you were interviewed to the settlement date for each of the plaintiffs, the cost could be many times higher. Not to mention this simply won't look good in the public spotlight, regardless of how right Google may be.
It's also almost impossible to prove on both sides. Even if Google has insane numbers showing how many young vs old people they hire, it's totally possible that the younger ones are simply more experienced with the technologies/paradigms Google is looking for. A judge might not see it the same way though.
Isn't it usually the defendants that attempt to drown the plaintiffs in discovery-related paperwork? This is an employment dispute, surely Google's own lawyers have a much better handle on the legalese of their own HR practices (and of labour laws in the state) than the plaintiffs?
(See, e.g., the Kevin Spacey lawsuit for a recent example in the news)
Again, the question is not who would win. It's whether it is worth winning.
Let me use a strong amount of hyperbole to try to make this part of the point.
Imagine a 3 year old challenges you to a fight.
They are completely and totally adamant about it.
You certainly could win.
Is it worth winning?
Or would it be better to try to give them ice cream and get them to stop bugging you.
Now imagine this fight will take 5-7 years :)
Despite what random comments on hacker news say, these are basically settled on a regular basis as cost of doing business.
If they were arbitration (heresy, i know) or some other cheaper/less intensive method of dispute resolution, google would likely (and often does) fight it.
But court cases are just really expensive and time consuming.
The average civil litigation takes 5-7 years to resolve.