I work in the motorcycle industry and I am a biker. I am also a yachtie, a hillwalker, middle-aged, atheist, non-smoker and many other categorised things, including being a car driver and a Mercedes driver. There are utter tossers in every category, no more or less than in any other. Some stand out more because they are not the 'norm', even when doing exactly the same good or bad thing as some other, more 'usual' category.
You should hear what many bikers say about car drivers (even though hardly any biker is not also a car driver) and in particular how drivers of some cars attract more criticism than others. Mercedes drivers are I'm afraid, higher up the list of those who should have been shot the moment they passed (or obviously didn't) their driving test. This will be because Mercs are not 'the usual', Fords and Vauxhalls are.
Of the bikers I met this week in my place of work, at least three are doctors, one is a paramedic, one is an offshore engineer, one an airline pilot, one a care assistant, then there is the retired cop who runs a ski chalet, another who is a driving instructor and one is a top industrialist whose advice anyone would follow. Also the 'Blood Bikes', guys who give up their own time to carry urgent blood products to hospitals and who get the stuff where it's needed by getting to the front of the queue. Amongst the cars in the customer car park have been Mercs, a Range Rover or two, an MGB, a Lamborghini and, last week, a 1913 Chalmers 5-litre.
We all hate to be associated with any bad behaviour, by having the same mode of transport or by being the same colour or religion or from a particular country of origin etc etc. So it is equally unfair to tar all of any category with the same brush.
Entirely reasonable however, to say, 'What irritates me about the way some people ride their bikes'. Which is what I trust the OP meant 16 pages ago.