Why is it so important about what you say?! Sorry, I don't get this fully, what is wrong with having some mods done to your bike, look at the factory 450's
The reason folks in his position need to be careful is for a few reasons, mostly because of their sponsors.
Here is a scenario to put it into perspective, a motorcycle company called Booger International sponsors you, which entails giving you free bikes, parts and some cash every few months. Now Booger International wants to sell as many heavy farm tractor like machines to all those out there in TV land, so they depend on you to make sure that at every opportunity, you tell people how great Booger bikes are...
Now someone bring you a machine from Swifty Engineering and asks you to ride it. This is the design that's lightweight, fast and tons of fun... but Swifty is a small company and can't afford to supply a bike deal like Booger.
What do you do?? Either you don't say anything about the Swifty machine or possibly say it's lousy
, or you are very careful about what you say about the Swifty.... No reason to get Booger International upset with you to the point that next year they refuse to offer the same deal to you.
It has nothing to do with modified machines and everything to do with sales and marketing... Booger wants to stay on top and does not want you to say that the Swifty machine is better then their machine... even if it is.
Hopefully my silly story has helped to explain it so that you understand.