People probably aren't upset about it because they don't know about it. This article seems rather obscure. Who has really heard of "foreskin fibroblasts" and would think to research this outside of a scientific setting? I tried googling seveal searches, and it is hard to come up with information on the subject. Looking up ingredients to TNS recovery gets nowhere, though I did find an interesting commentary (dated 2007) here:
You can look up foreskin fibroblast if you are familiar with the term (as provided in OP's article). But again, not exactly an everyday term. If you google a generic "human fibroblasts", you have to sift through numerous sources in order to find references to the use of neonatal foreskins as a tissue culture.
For instance, this site states that Dermagraft treatment for diabetic ulcers is "derived from neonatal foreskin". http://jdfc.org/2010/the-use-of-human-fibroblast-derived-dermis-on-post-surgical-wound-dehiscence-a-report-of-two-cases/ You have to really read the article to notice this though, and I doubt many people considering advanced treatment for foot ulcers are seriously researching in what culture the skin in grown. To give people credit, it's not a typical question to ask your doctor.
Even if they did, there are people who would see this as a positive thing. If there is a part of the body that isn't used/needed, why throw it away when you can put it to a good cause? Sort of like organ donation. I'm not saying I see it this way, but I'd be willing to bet many people view this as very useful and wouldn't think twice.
I also doubt all or even most foreskins are utilized for scientific purposes. But I do wonder whether consent is required for a doctor/hospital to sell foreskin tissue to other companies. Consent is certainly needed for organ donation or participating in a study, but I really don't know whether parents would even be asked what they prefer done with a part of their son's body that would have been disposed of anyhow. You don't see parents of circumsized babies discussing aspect his amongst the debates.