I'm a web developer in a marketing company. What you said is partially true, especially if your management doesn't really understand development (highly likely.) However, if you are able to look at the work that comes down, and come up with better ways to do it and engage management (rather than just being a set of hands to do their bidding) you can increase your value. You will never be as valued as you would be at a tech company, but you can try.

That said, there are a number of small development companies that focus on marketing. Meaning, they are small developer run companies that take on contract code work for marketing firms (mobile apps, HTML5, etc.) and they are by default developer friendly. If you're a good dev being beaten down by management in a marketing firm, then either find one of these companies or go start your own.