From my limited experience, it's a lack of the kind of systems thinking present in companies like Stack Exchange, and present on the High Scalability blog, that results in a poor architecture.
And this is compounded by people who have little ability to troubleshoot performance issues. It's quite easy to hunt down the cruddy SQL queries in a DB, or realize that you spinning rust is too slow. But when it starts to come down to things like a blocking network fabric, which has some big fat buffer between two servers, that is killing your transaction speed - many will just start to blame the devs.
Of course, the second point is compounded by the first - the less systems thinking that went into the design in the first place, the harder it is to produce accurate hypotheses about the system in order to troubleshoot.
Whilst there is a lot to be said for the "right tool for the job", if you watch an artisan crafting something, you'll realize that despite having a huge number of tools, they actually get by with relatively few. This is a generalization, but they only use the full range when doing something new, solving a particularly tricky problem, etc. "All the gear and no idea" is certainly applicable in many start ups.
And this is compounded by people who have little ability to troubleshoot performance issues. It's quite easy to hunt down the cruddy SQL queries in a DB, or realize that you spinning rust is too slow. But when it starts to come down to things like a blocking network fabric, which has some big fat buffer between two servers, that is killing your transaction speed - many will just start to blame the devs.
Of course, the second point is compounded by the first - the less systems thinking that went into the design in the first place, the harder it is to produce accurate hypotheses about the system in order to troubleshoot.
Whilst there is a lot to be said for the "right tool for the job", if you watch an artisan crafting something, you'll realize that despite having a huge number of tools, they actually get by with relatively few. This is a generalization, but they only use the full range when doing something new, solving a particularly tricky problem, etc. "All the gear and no idea" is certainly applicable in many start ups.