Why Don't Local Audio Dealers Provide Tube Testing Services When They Sell Tube Gear?

For over 40 years I have supported my local audio dealers. I gladly pay more for their expertise and service. Some of my dealers have a store front, and some work out of their home. In either case, I always support them.

I have an "all tube" system, with 19 tubes, including my DAC, Preamp and Amp. Most of my tubes are NOS, and I like to "roll" many tubes. When I need to test a tube, or want ensure that the tubes I've purchased are indeed a "matched pair," I would really love to depend on my local dealer(s) to provide that service. 

For the most part, I have been very fortunate to buy NOS tubes from reputable dealers. Not always though. And when you are buying hard-to-find expensive NOS tubes, you sometimes have to take your chances.

At a minimum, audio equipment dealers should be able to provide "on-site" testing for the tube equipment they sell. Ideally, equipment dealers should be able to do "on site" testing of other tubes as well.

If a local dealer were able to service my audio tube testing requirements, I would seek them out for any new equipment purchases (including non-tube gear). That's part of having a mutually beneficial dealer/customer relationship.
Getting (and maintaining) good testing equipment isn't cheep, but it seems like a good business decision for maintaining and attracting new customers?