Web Services & Packet Radio ... But! But! But!

When discussing web services and packet radio, I hear a lot of buts ...

• But XML is too inefficient to go over 1200 baud links!
  
  XML in its native state is very inefficient; but that inefficiency also gives rise to incredible compressibility; you can shrink XML in ratios of somewhere around 8:1 .
  
  
• But we've tried (HTTP, TCP/IP, etc.) over packet radio and it's just too slow to bear.
  
  All of these are probably in support of interactive user sessions, which web services is not (usually).  Web services are computer to computer communications, and usually do not have a direct impact on the UI.
  
  
• XML is very bandwidth inefficient
  
  I don't think there's a bandwidth shortage.  As far as I can tell, most packet nodes sit idle almost the entire time; that means lots of wasted bandwidth.
  
  
• HSMM (i.e., wifi with higher power levels or better antennas) is much better for this sort of thing.
  
  It's much better for running a traditional TCP/IP network, for sure.  But web services do not require  TCP/IP or HTTP -- those are just one of many ways to deliver web services.  And while HSMM delivers high speed, it is also a very small niche compared to 2m packet and doesn't have the ability to easily blanket a community with a signal.
  

 To be fair, when I raised the question, it was very narrow (has anyone tried this?) without a lot of explanation of why.  I'll try to answer why in another post soon.