why do companies mess with their agency's ideas?

No agency can survive without its clients but companies can be frustrating people to work for.

Last week I saw a new advertising campaign from an established operator, created by an agency that has a good portfolio of work on its website. They certainly didn't look like a mickey mouse outfit so one would assume they charge decent money to deliver their service.

The idea was a decent one. You could see where they were coming from and with the right execution it had the legs to be a good campaign. Then, by the looks of things, the idea got passed over to the client who proceeded to work their creative 'magic' on it.

The result is a poster with far too much text, dodgy colour combinations, too many logos and the obligatory dodgy image of a bus. It looks like a poster of two halves - one done by the agency, the other done by the client.

Now I'm pretty sure no agency worth their salt would have proposed what eventually went public, and I doubt very much the finished article will appear on their portfolio page.

So why did the client pay the agency for their ideas and their advice, when they were going to do what they wanted anyway? Budget? Ego? The office junior knew his way around Indesign after a day course?

Paying for the best ideas you can afford then trying your best to ruin them. Baffling.