Why can some bikers be such ?

I ride a 98 trick blade i'm no joey dunlop thats for sure i am within the law and totally legal i dont speed unless i have to overtake, 20 years on the road i've nothing to prove to anyone. but last year my nephew was out the front of my bros house washing his CBR 125 which i bought for his birthday, his dad paid for the lessons anyway these s riding 2 up on a 750 gixer rode past and the pillock on pillion shouted "aye yer bike" at my nephew. sunday afternoon slow traffic i tooled up and got on the blade. i wouldnt have minded so much if they were going with the flow of traffic and then shouted but the bloke riding slowed down beside my 17 year old nephew so his mate with no bike! could shout! i sat behind them flashing my lights tooting the horn, i got them to pull over did a u-turn idles over beside them lifted my visor and shouted "aye yer skills" then i spat a hawker at the pillion kicked into 1st throttled up and blasted them holes into dust.