If those games weren't expected to sell well in the West, why would they even waste time localizing them in the first place? If Sony doesn't have faith in their own IP, then why would a 3rd-party publisher care?
Like insanolord said, companies like Atlus; NISA; XSEED; etc. want these titles because they
know how drive up hype in and sell niche titles to the maximum possible audience for such games. The perfect case in point is when Sony declined to bring over Demon Souls to NA when they published the game in Japan. Instead, they sold the NA publishing rights to Atlus, and Atlus turned around and made the game a relative phenomenon in North America.
Likewise, after Reggie refused to bring over The Last Story (which, Uncle Bob, he would have
had to have done b/c NOA had first say on publishing that game in North America), he made the extremely rare move of selling the publishing rights to XSEED. It's now XSEED's best-selling game ever at over 50,000 copies reported sold, and considering how XSEED's lasted several console generations now selling much fewer copies of other titles, that worked out very well for them.
Niche titles depend on smart marketing to the right audience at the right time with the right presentation (and in limited quantities), and smaller companies excel at that. That's why they care when bigger publishers pass over bringing certain games over.