Here's the reasons for heating up the oil before changing:

 If you change the oil cold any particulates that have settled in the engine probably will not drain out. Yes one of the reasons for changing is to get new oil and filter installed. But the most important reason is to get the "dirt" out. In theory if you could capture all the dirt in the filter and only pump clean oil through the engine you could extend your oil change interval to many additional thousands of miles. On the other hand if you don't get the dirt out, adding new oil to to a lot of dirt trapped in the engine equals marginal protection from the get go and a lot of wear that could be prevented.

 Hot oil drains better. If you started the drain process in two bikes at the same time, one hot and one cold, the hot oil will drain out faster and more completely way before the cold one. I know this is probably no big deal if you are taking your time on the weekend, but again you are likely to do a better job of doing a complete change if you don't have to wait 10 extra minutes for the oil to drain out. Most of the time we like to get done and get on the road. 

 Yes there is oil throughout the engine after it has been running, but being hot it tends to drain out quickly. You will get a more oil out hot than you will cold. 

 I know for most of us the above points aren't worth worrying about, but this is why you should change oil warmed up, preferably after at least a mile or so of riding to really get it running at full flow. 

 Will the bike last for many years without being picky? Sure it will. It's just a matter of principal. Some people like doing things by the book, for good reason. Others don't like to sweat the details. The person that sweats the details (all the details) will in general have more worry free time in the saddle without unexpected down-time. 

 And the lucky person that ends up being the next owner of the bike will really benefit as well. I know the type of person I prefer to buy a used bike from.

 It's not that big a deal, it's your bike, pick your method then and focus on riding. Good luck.

PS - I type slow, most of what I said was said above while I was typing. So to that I say, Ditto. My wife always tells me that I'll take you all the way around the block when I'm trying to explain something.