Very true, Waxman. However, many IBA's do not even use a wheel cleaner. Wheels only get as clean as the presoak that might get on them and then sprayed off will do (or the rocker/wheel blast, which is usually only water). It is fine for dirt, mud, salt, sand etc. but most IBA's - even with a friction wheel scrub do not do a thorough job of break dust removal - especially if you have tire dressing gumming it up, or if it has rained and then dried. Tunnels truly have the edge with wheels - more equipment options and sometimes the use of manual labor.
I agree for a detailer break dust is great, however I don't see many IBA's doing a good job with wheels, unless they are hand prepped. Sure - customers can prep their own wheels in the s.s., but it is a pretty small amount of customers that will prep wheels for $2, then wash the car for $8 in the IBA. Not the money so much, but the time and hassle. Using the s.s. defeats the convenience of the IBA.