First, because of The Method. Kaley Cuoco-Sweeting has done an excellent job cementing herself in the "hot single blonde"-type. As 'The Method' works best when one's brain is consistently in the same situation as one's character, and as the 'hot single blonde' brain-space is a very tempting place to be; the new Mrs. Sweeting needs to stay away from that brain-space in order to cement her 'cast' in the "hot MARRIED YELLOW-HAIRED" type. Also (and yes, this is homophobic!) the relationship between Leonard & Sheldon is ... uncomfortable to think of seriously---and I know, it IS a "sitcom" and therefore not S`POSTA be 'thought of seriously'; but ... bordered on "unpleasant" And I know Leonard slept with 3-or-4 girls during all that time, but I still think he & Sheldon got to know each other a little too 'like a married couple' ("... and shake twice for Texas"? Come On!) I'm ... I'm mostly writing this to get over my jealousy of Kaley's speech-therapist---just like I'm jealous of mean rich-guys who steal away girls that would love me if money were no object. Trying not to bring up the possibility that the marriage may show a conflict-of-interest in Mr. Sweeting's practice (or the practice may conflict with the marriage)---... I didn't say that!