The Ti/Al guns were fine from every perspective except one: they were expensive .38 +P guns and there were greater sales to be made putting the Ti cylinders into magnum revolvers once S&W figured out how to use scandium alloy for the frames of those guns. The 442 and 642 (and similar) stayed because they had a very different price point and market segment.

Personally, I'd rather have the 342 than the 360, and I do have several of them.