Sergey appears to have attitude issues and the IOTA team have serious damage control issues, but the MIT team also, maybe wisely, appear obstructive at certain important points. In paticular the probability of attack in the wild seems a valid question that was never dealt with by the MIT team? (Disclosure: I'm not invested in IOTA one bit, nor is anyone I know)

What I witnessed after reading through all those letters is a common clash I see over and over of two types of cryptanalysts: Those whose knowledge grew in resource expansive environments (internet/cpu space) and those whose knowledge grew in resource constrictive space (e.g. satellite broadcasting). In particular they clash on the idea that there can ever be a valid use case for a less-than perfect security schema, so-as-to provide certain desired resource benefits, while still being sufficiently secure for a specific use case.

Cryptographers dance around who has perfect security at heart, never getting down to the issue: that they disagree on necessary trade-offs. By the time they do get to it, one will disengage entirely from conversation and assume the other is just stupid. That has happened here (both sides I think). It's a common outcome.

(Disclosures: I worked as a software+hardware reverse engineer, not cryptographer, in the satellite TV space. So I'm not anything close to an authority on the topic but was around these debates often.)