The Grand Prix Sicilian as well as some c3 lines, is an excellent choice for attacking white players. I don't see the boring or unambitious part there.
And even the h3 var. against Sicilian Najdorf can put the board on fire.
More boring is usually something like 1.e4 e5 2.Nf3 Nf6 with a lot of trading, or 1.e4 e6 2.d4 d5 3.exd5 and trade everything
But he should play the open sicilian if he wants to maximize his probability of getting an opening advantage.
I don't know why he doesn't play 2.Nf3 and 3.d4 against the sicilian, well, maybe 2.c3 players are less risk averse, maybe he wants to bore his oponnents.
I see your point as per the sicilian, I suppose. I don't play sicilian and when I'm white I play a Grand Prix or c3 - the closed sicilians
How unambitious. It irritates me so bad when my opponents play such passive boring openings.