Engineers are skeptics by nature. They make decisions based on facts, not convenience or speculation. When they take risks, the risks are calculated and supportable by assumptions based on facts. They are genetically uncomfortable with Sales and Marketing people. One of my clients, a software engineer who founded a very successful company, never understood or trusted his own S&M team. This is why, on the whole, the founder/engineer is the most troubled by the language of a market based definitive purchase agreement.
Reps and warranties are an allocation of risk, not a reflection of facts. For example, a standard IP rep assures the buyer that the sellers technology does not infringe on any other intellectual property. How could a CEO possibly know this to be true? They can't. Instead, they have to think about it as an allocation of risk. The buyer is paying a substantial amount of money for IP, but it's not worth the price they are paying if it is infringing (and yes, we can sometimes sneak knowledge qualifiers into this scenario), but not with the buyers paying full value for early stage deals.
Another example is certifications. A CEO is often asked to represent that all of the necessary certifications and permits for their business are in place. Again, how can they possible know? They can't know for certain, and they will need to take calculated risks.