Oh you entirely intend it to be offensive, which is fine.
Believe what you want. I will say again that of the three "I can't believe it!" responses thus far, I'll bet zero have ever even run their profiler. Ignorance, as they say, is bliss, and in many cases is perfectly fine.
I meant offense to your team, not you. Even though I have used profilers such as NHProf or Ants quite extensively in .NET, you hardly need to use one to understand the implications of a Linq statement - particularly an IEnumerable based one. If your team doesn't understand simple concepts like iteration or projection (and allocation) then you have an uphill battle to fight regardless of the tech you choose.