While I think that we can all agree that the "mine is bigger than yours" mentality has driven many to gravitate toward two camera companies that shall remain nameless, the rest of this statement is just downright odd. First of all, the OM System is not a "compact SLR". It is one of the finest and extensive 35mm camera systems ever devised, with over thirty years of active production. Its small size and light weight were consequences of superior design and innovative engineering, not some desire to make a cheap, throwaway camera.
As for not offering more than "token compact lenses", you have obviously not seen the numerous stories of OMs' dependability and longevity, including 4T's surviving 20 foot drops. The OM-4 was carried into space by NASA with the only modification needed was replacing the Naugahyde covering! I won't even go into the laundry list of technical innovations embodied in the OMs (including some of the most advance metering ever found in any film camera).
While Pentax did make a "compact SLR" it was called the Auto 110, not the ME/MX. Any good engineer knows that there is no challenge to making something that is big, heavy and clunky which happens to work just OK.