JT9-1 => JT65-HF

This afternoon I decited to make some QRM on 28 MHz band. First I tried to find any contact on JT9 -mode without success. After checking conditions on 15 meters I came back to 10 meters. This time I tried JT65-HF. I saw some weak signals and tried to call CQ. PSK-reporter indicated that my QRP was quit loud in France: three different stations announced me. Finally, I was quit surprised to see very strong singal on my "waterfall", - 6 dB. Well, nice DX-station, N4CE, called me back. There was no problem to make a QSO. JT-modes are so nice for QRP. The only pity thing is that there sounds/ looks to be more and more QRO stations - signals more than 50 W on these modes. Why - why they need so much power?