I am a member of Thailand Elite and I am met with a golf cart every time I arrive at BKK so yes, I do take serious exception to the increasing number of bus gates at BKK. I cannot ever remember it taking only 5 minutes to get from the apron parking spot to Immigration at Suvarnabhumi. I do recall it taking only that long at Jakarta and Dhaka because Business Class passengers were bussed separately from Economy class passengers.
Your comments re size of people is rather strange........I am not a small person but if I was walking down the steps from the aircraft and an apron control person asked me to wait for the next bus then I would do just that. Neither my size, or the size of the individual making the request would have any bearing on my decision to comply.