PR is a fuzzy science at best, and I'm no expert, so I won't claim to know how wise the press release is. I'm sure that Cloudant was excited to acquire a large customer (rightfully so), and that issuing a press release can impress investors, other potential customers, and the start-up community.
It's the second argument that I vehemently disagree with. If some corporation feels that it would be unethical to do business with Monsanto, then by all means refuse to do so. But to argue for an embargo against Monsanto, and imply that any company that does business with Monsanto is in the wrong, is wildly inappropriate and unfair. No doubt countless other corporations do business with Monsanto: PC manufacturers, construction teams, office suppliers, not to mention utility companies that keep Monsanto running, shipping companies that deliver to and from Monsanto, etc. I agree with pg that to argue for an embargo against Monsanto is quite extreme, and it's unfair to hold Cloudant to such a standard.