You only complain about it, because you have no idea how worst are some Portuguese commentators from a Portuguese sports network. Now, they're the ones who don't know sh** about what they're talking about.
The guy who commentates the Indycar Series, he sucks so bad that he once started to invent new facts about how the series were formed.
The NASCAR guys they are not that bad, but sometimes they start to act like they know more than they actually know.
And Moto GP, please, the commentators talk to the spectators as if they were seeing Moto GP for the first time. I guess at sometimes it's cool for people who is really watching it for their first time to learn a little bit about the sport, but I guess there's a lot more people who previously followed Moto GP in Eurosport watching Moto GP now in their network, 'cause it was the only option, than first timers. So, I guess some people like me, were like "WTF???" when the commentators were stating that this year's Barcelona GP was the best ever in Moto GP history.
In conclusion, the ones who look like they're watching the series for the first time, are the commentators themselves.
The only ones that I think that are reasonable are the F1 guys. 'Cause they've been commentating the sport since forever.
Now, the ones who you really can tell they really know what they are about (Portuguese commentators wise) are the ones from Eurosport, especially the one from WSBK. That guy really knows a lot about the racing and the bikes, to the extent of already have tested some of the bikes (the road version), and compare them to the racing bikes.
But this is just my opinion
Cheers. Take care.