For me this was the most fruitless decade of the last ...100 years in terms of guitar composing or even arranging...
the interest about guitar music seems to decrease in a geometric progression
Hmmm... it's tempting to think that in the internet age we are all up to date and informed very quickly, but the newest music takes a while to be assimilated -- even the most over-played & over-recorded guitar works of an era seem to have a 15+ year lag before they take off. So it's impossible to say what has been written in the last decade which will take the guitar fraternity by storm.
A quick unscientific test at sheerpluck.de doesn't support the idea of a decline in interest; here's the gross number of compositions for solo guitar noted there by decade:
When all the data is collected I'm sure the noughties will surpass the nineties in number. By Sturgeon's Law* there should already be about 217 good
compositions from the noughties, but it may take us one or two decades to identify them.
I think the interest in art music per se has become more niche -- I suggested here viewtopic.php?f=1&t=66264
that interest in guitar music in the 1960s & '70s was probably disproportionately high, so now it has got a realistic slice of a smaller cake. But global communication means that "niche" interest groups can find each other much more easily than before, so at the same time as global interest declines mutually interested parties nurture each other much more than before.
And don't forget the 1990 composition "White Night Serenades" by Grigori Korchmar got a recording in 2011!
*Theodore Sturgeon said, "90% of Science Fiction is c**p, but then 90% of anything is c**p."