Because, the issue of diplomatic relations itself with Korea was unsolved, and there's a remains existence who was a Seikan-ha (supporters for subjugation of the Korea) like Masaharu IJICHI, and, in the imperial decision made by the emperor, it wasn't mentioned to "cancel" dispatching an envoy to Korea, but simply said to "postpone" it, and the reason they stated was only the problem with Russia that has been the most tangled at that time.
なぜなら、朝鮮との国交問題そのものは未解決であること、伊地知正治のように征韓派でも政府に残留した者も存在すること、そして天皇の勅裁には朝鮮遣使を「中止」するとは書かれず、単に「延期」するとなっており、その理由も当時もっとも紛糾していたロシアとの問題のみを理由として掲げていたからである。