Dear IMO, Shell, Caltex / Havoline, Mobil1, etc. are some of the well renowned, reputed and respected brands, and their sales volume is much much bigger than that of Liqui Moly. Even this point is sufficient that these oil brands come factory filled in engines of some very reputed and respected automobile brands.
Shell, Total, Caltex / Havoline, etc. are available from many shops (when compared to Liqui Moly) and at very reasonable prices compared to it.
If I can recall correctly, I have never said that Liqui Moly is bad. Liqui Moly may be good, but to me, it is expensive, and accordingly, not value to money. Shell, Total, Caltex / Havoline offer more value to money.