With good planning and research you know exactly what you can and most important what you can't do before you start a new project, at least we did at the company I worked for.When you say 'short-sighted design decisions', are you sure you didn't mean to say 'technical issues they were unable to overcome'? The end result is the same, but the narrative is quite different. As a general rule, when you dont get what you want don't assume people didn't want to give you that.
We sometimes had to disappoint certain clients because they were asking for things we knew we couldn't deliver technically. Sometimes we knew we could deliver more then what the customer envisioned too.
When you start a project and half way through you find out you can't realise it then you've got a serious problem regarding planning and/or research, I'm not even talking about the wasted resources and funds.