And you are being told that everything you are saying is clueless

A bike is not a frame and fork - it is the sum of all its parts. You part up almost any bike in line with the quality of the Team Mongoose bikes and you are looking at a $1,000+ bike. Instead you get it for several hundred less buying it complete from them. That's a big savings for a bike that really is incredible out of the box.

If your bike is better, odds are good that you parted it up yourself and that you spent a lot more than the complete Mongoose cost. It doesn't make their bike suck no matter how much you want it to though.