The 2023 MotoGP season has seen both of the series' Japanese manufacturers struggle for form, with Yamaha scoring just one podium in seven rounds and Honda's Americas GP win with Alex Rins proving to be a fluke result.
This coincides with a shift in balance on the grid towards the European manufacturers over the last year, with Ducati leading the way from KTM and Aprilia.
The German Grand Prix weekend was particularly bruising for Honda, which was two riders down after Joan Mir and Rins were injured in separate incidents.
Five crashes for Marc Marquez forced him to withdraw from Sunday's race.
Asked about some of his MotoGP rivals, Miller – a distant sixth in the German GP – made a barbed dig.
"We're [KTM] the only ones not complaining about our motorcycles and we're actually trying to do something about it to fix it," he began.
"All they do is throw their toys out of their cot and say 'my bike is shit'. It's simple as that.
"Why are they shit? Because they kicked 99% of their engineers to get his engineers, his guys in there, and now they're f****d and he can't even make it past a lap.
"So, it's their own doing. Everyone wants to complain about their own bikes, nobody wants to do anything about it.
"Shut the f*** up and get one with the job. You're paid to ride a motorcycle, not to be a f*****g princess and complain about your bike."
It's not clear exactly who the "he" Miller is referring to.
However, if it relates to Marquez then it is not accurate as the Spaniard only brought crew chief Santi Hernandez and chief mechanic Carlos Linan with him from Moto2.
Miller led the early corners of Sunday's German GP, but a scare through Turn 11 on the opening lap dropped him to fourth and he couldn't recover.
Eventually finishing sixth behind five Ducatis, Miller says the KTM lacks the same early race speed as the Italian bikes.
"We're missing a little bit," he explained. "I was pushing my maximum, I had a moment and got caught up in the group there.
"We've had decent pace all weekend, [I'm] just missing that little bit of outright speed.
"We were closer here than we were in Mugello, but just missing those first couple of laps, a tenth there, a tenth here.
"Those Ducatis in front are able to find that little bit extra pace and then button it down. Ours is rather consistent the whole way through. It's not bad, but it's not good in the beginning."
