these files come from a well known distributor so there is little to no concern of anything malicious

I've read stories about manufactured floppies and/or CDs with viruses. I've read stories about manufactured audio CDs with root kits. I'm not talking about random stuff you pull down from the seedy side of the internet, either. I'm talking about big-name manufacturers.

The company may not be malicious, but the guy who produces this data may be having a bad day, found a new job, and is going to quit tomorrow.

In my experience, it's actually easier to use placeholders than not. On top of that, it's more secure, and may even be faster at runtime (for example, there's less for the DB server to parse and mangle, plus if you prepare a single query and use it multiple times, there's a bunch of text that only needs parsing once). My experience says that there is no downside to using placeholders. Arguably there is a bit more code to deal with (especially if you're manually binding variables), but there doesn't have to be, and if you try to compare the amount of code for an insecure (not-working in your case) snippet vs a secure (working) snippet, that's apples and bananas anyway.