God, this reply couldn't be worse:
"Real five nines network infrastructure takes significant capital investment."
No, it doesn't. Overly complex, corporatized infrastructures designed by committees in meetings - that takes significant capital investment. Simple infrastructure designed by hackers can achieve bullshit metrics like "five nines" without breaking the bank.
"And that's before you get into things like establishing colo at major IX points, serious core routers that cost $15k each"
Establishing colo at a "major IX point" is a few emails and phonecalls away. Your salesperson will fall all over him or herself and waive the NRCs to get you in there. It doesn't cost much, even for a full rack with 20 or 30 amps. If you're just doing networking, you won't even need that. Then you get a fiber cross connect to he.net for 10 or 20 or 40 gbps and you're in business.
You can buy very, very nice used routers and since you're a hacker and not Mr. Enterprisey IT guy, you can run it and support it yourself.
We had many iterations of this exact critique in our early days - explaining how we couldn't possibly deploy this volume of storage without fancy bullshit enterprise solutions from EMC or Compaq and how we couldn't possibly run a global storage network without fancy routers (we currently own zero routers) and fantastically complex clustering and failover ... and 17 years later we're still making it all work just fine.
Fuck those people. Fuck those school trained, passionless, non-hacker, no-talent-pussies.
Good luck with your mesh network!