As cool as that sound, not everybody can afford that.

Besides money (or lack thereof), a second consideration is the ability to just pick up and go. A good friend of mine from Europe decided to "skip" winter and spent 6 months in SE Asia with his wife and 2 daughters. He owns a commercial space in a city (now it's a restaurant) and he doesn't have to work for his income. He just cashes in the rent. While he CAN do stuff like that; I have a full time job and I can't just take a 6 month break.

To answer the OP: why do we do it? First of all because it's possible (for some). I've done all sorts of weekend getaways, but now with a 1 year old son it's less of an option. So you need to have the freedom (time) and the money (or miles/points).

As for stuff like family/friends thinking one is crazy for traveling, it's easy to understand why. If they had the freedom and resources, they too would likely travel. When you have a bunch of miles and/or hotel points... what else are you going to do?