For me it wasn't a question of brand loyalty, it was simply the fact the Commodore produced the best & most innovative machines for their time...
Way back end of 81 start of 82 what were the main choices a ZX80/81 which was nothing more than a big calculator or the VIC20 with full size keyboard, slightly better graphics & far superior sound... no brainer that one...
Then came the C64, but by this time you had all sorts of other computers to choose from , Spectrum, Dragon, Oric Atom & Amstrad to name but a few, but the C64 won out again 64K RAM, superior gfx, sprites and the SID chip that made all the others sound like some old fashioned alarm on the first digital clocks... again a no brainer...
Then of course for me in 86 came the most advanced and elegant (OS wise) home computer ever conceived the Amiga, no need to explain that one...
Never parted with either the VIC20 or C64 because by then i had bought literally thousands of tapes for them and there was no way I was ever going to sell them even though they couldn't be used on the Amiga. So I just hung on to them so that I could still play those thousands of games while I began building up my new Amiga software collection...
By 92 and the A1200, for me there was no need for another computer (still never understand why people always bring doom into the equation) and from that day to this it's always been the Amiga and nothing else...
If CBM had ever brought out a new machine it would have to have been something as radical and as special as the C64 & A1000 were for their time. I certainly wouldn't have bought it just to play Doom and if that's all it was really capable of doing then I'd have passed on that one...
Still more than happy after 30 years of using these brilliant machines and will be until I kick the bucket, no PCs or latest consoles for me, the VIC20, C64 & Amiga cover everything I need from computers...
As for the Doom question... WHY...
(PS:Couldn't answer the poll as nothing in it applies to me....