Yes, the power/weight-ratio has increased.

I have not done any research about this, but the new F800GS is heavier then the R80G/S (and R80/100GS dependent on model) which is up to 27 years older. The new Tenere is heavy, is it lighter then the old one?
But it’s true for lots of bikes.

Maximum power has increased during the years, torque have also increased but not that much. (There are exceptions here!)
It’s difficult to make an engine with both good torque in the cruising range and high maximum power. My theory is that the focus on maximum power leads to less low end torque then if we had start focusing different.

Some interesting points have been mentioned here .

When you look at torque ,you should also look at where in the rev range the bike produces maximum torque. Ideally you should operate the engine at an rpm that is slightly above the max torque produced .
Then as the bike comes under increased load ,as in going up a hill ,the engine will have a torque "back up" and climb the hill easier .Sometimes called lugging ability this is easier to demonstrate on a graph .

It's very difficult to compare bikes because they produce the max torque at different rpms -
these days 4000rpm is not very fast .
The 650 VStrom produces it's power higher up the rev range -it revs to 10,500 and it's not a very fast bike by modern standards.
Smaller engined modern bikes can deliver the goods by increasing the revs to compensate for the lesser torque ,modern materials inside the engines and improved engineering tolerances mean that they can do this reliably .

I have an XS650 Yam that revs to 7500 ,if you held it at 7000rpm for any length of time it would self destruct .A 650 Vstrom will do 7000 rpm all day .

Frames are better designed these days ,forks are fatter, swingarms are beefier, longer and are usually monoshock ,engines have emission equipment and exhausts have cats and extensive baffling ,all this adds weight .
But usually it means that the frames are capable of handling a higher load -if you want to load them to the maximum .

Weight is the enemy , if you can travel light you will get better performance, better fuel consumption and your bike will be a lot easier to handle .It's not much fun trying to lift a heavy loaded bike on a 45 degree rockstrewn downslope on your own .If you never travel off tarmac ,it may not be a problem that you'll have to face .

So in many ways the modern bikes like the Versys , VStrom 650 and the F800 GS are a very good thing ,they will give the performance of the big bikes for less money and less weight ,you'll just have to get used to revving them a bit higher .

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