From the article:

In a post to Capcom's message boards today, a representative emphasized that wasn't the reason for the game's save system.

"There was no intention of lessening the experience of the game," said Capcom community specialist Shawn Baxter in his post. "Essentially, RE: Mercs was treated like an arcade fighting game. You unlock characters, levels, etc and they just stay unlocked as they would in an arcade machine. There was no hidden motive to prevent buying used copies. It's not some secret form of DRM. It's simply the way we designed the save system to work with the arcade type of gameplay."

Baxter went on to stress that the game doesn't have a traditional story mode, and every mission is replayable at-will, so no content would be inaccessible to a second-hand purchaser.
http://www.gamespot.com/news/6321800...ll%3Btitle%3B1

This whole thing is absolutely ridiculous.

Is it a design decision that frustrates those who enjoy/depend on the 2nd hand market?

Yes.

Is it a design decision that frustrates the OCD in the gaming community that feel a compulsion to replay a non-linear arcade style game and not have any previous data imprint on it?

Yes.

Is it ultimately a poor choice by Capcom to have implemented such a feature or lack thereof?

Based on the reactions of the gaming press and by extension a majority of the gaming public, apparently the answer is yes.

But ultimately, do we REALLY believe that it is some grand conspiracy designed to "kill used video game sales"?

Really? Do we really really believe that this is anything more than an annoyance to the compulsive set who can't deal with the taint of another gamer having seen the "you've unlocked a level!" message or saved a high score or run-through time on the used cartridge that they're buying?

The gaming press has attempted to crucify Capcom over this, and Capcom have made multiple public statements refuting the allegations that they're out to hurt 2nd hand consumers.

Thats it.

There's really nothing more to be said other than disagreeing with their design choice.

Hopefully it's a lesson learned for them and they throw the option into their next arcade style game to avoid similar bad press.

Seriously.