I used to work in corp dev at a big tech company (not a typical silicon valley). This is pretty much spot on by Paul Graham per usual. I was typically the one doing the initial contact with companies (as a junior analyst on the team). I always found it interesting how many HUGE replies I got back from startups. I rarely ever saw a company take PG's advice and say not interested. Companies that were over-zealous were definitely thought less of while companies that played a more aloof game were chased.

Also I can say first hand all of the shady deal playing is absolutely true. The members of the due-diligence team and even the corp dev director you are dealing with are NOT the final decision makers. We are building an internal package that makes it appealing to the corp dev VPs/CFO to bless (and take to the CEO to bless sometimes). It's several layers of vetting and it's just as tedious and bureaucratic as it sounds.

I will say that the due diligence team typically will want the deal to be successful. No one wants to put in all that work to not buy a company. Corp Dev's job is to buy companies so having deals reach the 11th hour and fall through is NOT good. They pride themselves on stats like companies evaluated/year (wide funnel) and having a small fraction actually go to due diligence and the buying process. At the end of the day though, they want to buy businesses.