K/D in Portal and official servers with bots.

I like to play with my friends on hardcore servers. These servers are popular and there are a lot of real players, except for a couple of bots to balance the teams. And I found that my K/D decreases after every match, even if I made a lot of kills in terms of death ratio. YOU'VE BROKEN THE STATISTICS. How can you not count the killing of real players? Why then count deaths in statistics? Then the statistics in such matches would be turned off altogether. Why spoil people's K/D?