Convenient! Comfortable! Time saving - maximize your precious holiday time - more time for the experiences and the explorations. You will save money! Less wasted time! You will not be subject to or experience quite a few not nice things. You will stay in nicer and less expensive hotels!  Greener travel!

Convenient! Comfortable!

No heavy luggage to lug around.

Time saving - maximize your precious holiday time - more time for the experiences and the explorations

No waiting for checked in luggage on flight arrival.   

   It can be an eternal wait: British Airways looses some ten bags on an average flight - I read.

  I usually sit at the plane's exit door and is typically out of the airport in a few minutes.

  Say you are going to catch a transport in a few hours. You want to check out a sight. If you have light luggage you take it with you and after seeing the sight you head for the transport. 

  If it is too inconvenient to carry your luggage you have to leave it  somewhere, then later come back to pick it up. This usually means a couple time consuming detours. If short of time you won't make it. 

You will save money!

No need for taxi because of heavy luggage.  

  You can walk to the cheap public buses which sometimes stops away from the airport.

 You can walk for hours to find nice accommodation. If overburdened with luggage you easily opt for the first hotel you find even if it is expensive and not nice.
  Sometimes though I have to fork out money: I had a very early flight. I had only the alarm of my wristwatch which would not wake me up for certain. I bought an alarm clock for a couple of dollars. Later I donated it to the locals.

  You can buy some 27 kg of stuff on your trip without having to pay for overweight.

Less wasted time!

I met a couple sitting midday at a hotel with all their heavy luggage. They had just checked out. The hotel refused to keep their luggage for some hours.
 

They had a flight 12 hours later and were going to just wait at the hotel - quite a bit of waste of probably precious holiday time.   

Pack light and experience more during your travels!

Other advantages

  It is not obvious to robbers that I am a traveler with all my funds and stuff on me.

  A friend commented: No, it looks like you have been to Seven Eleven shopping groceries. 

  In a travel guide I read: "Don't make yourself a target on the streets. Carry as little as possible." 

You will not be subject to or experience:

Total loss of or theft from your back pack which you checked in or left in the baggage hold of a bus or train. 
  (In a train station my friend was busy talking to two nice ladies - and his back pack disappeared from his side.)
  Bag snatching.
  That you just make it onto the next plane when changing planes - but your checked luggage doesn't make it.

You will stay in nicer and less expensive hotels!

I traveled with a friend. We got off  a bus and walked some 30 minutes downhill towards the beach. He had a 20 kilos, 44 lbs, back pack - I had a couple of kilos, 4 lbs. 
  The first hotel we saw was some 200 m, yards, from the beach. We checked it out, nothing wrong. I stay here! my friend said. Why don't we check out what they got down there with sea views, terraces or what not, I asked.  No! he said.
  I walked down to the beach to see what was there. I didn't find anything spectacular this time - but you never know.
  I think my friend was too fatigued to consider walking another 200 m, yards.

  Part of the fun of traveling is to stay in (relatively) nice places. When possible I like e.g. sea and mountain views.

 Greener travel

If you keep your luggage weight down you keep emissions of green house gases down as less energy is required to manufacture and transport your luggage.