One of my friends used to work at Apple. After one particular grueling stint of 14+ hour days, management decided to give them a thank-you. In the form of vouchers. For frozen dinners. Meanwhile, all of his friends worked for Google, we got gourmet food every meal of the week as a standard perk, and we were usually home by 8 or 9 PM rather than midnight. It's sorta like "Your 'thank you' is really more like a giant '…
Crunch time is fine when its uncommon and unforseen. Otherwise it is a manag3ment failure. Perhaps its deliberate failure to respect peoples personal life, but that's still a failure. I've worked plenty of places where crunch time is uncommon or nonexistent. It doesn't have to be that way.
Basically, if you believe that hitting a deadline is worth having overall less productivity for, you can reasonably crunch for 2 weeks, and have the third week as an acknowledged low productivity week, and it might be worth it. Anything much beyond that is counter-productive on pretty much all axes and a strong sign that management is incompetent.