Maybe because if my $60k BMW or my $4k plasma tv dies, I can't afford to replace it. However, I can afford to replace my $500 computer or my $400 regulator. Moreover, as Gilligan points out, these items aren't without a warranty, only without a manufacturers warranty. Now, while I might not trust the local dealership to eat the cost of a lemon BMW 7, Leisurepro seems more than willing to eat the cost of a computer or regulator. (And, just to forestall this argument, the lack of warranty doesn't diminish the manufacturers' potential liability for producing a defective product.)
Incidentally, I don't have any experience with LP's warranty. I've only bought a few things from them. But I do have experience with Scubastore/DiveInn. A year ago, I bought an Uwatec SmartPro from them. Then came the e-mail from them concerning the recall. It was one week before a trip to Fiji. They promptly agreed to give me a store credit for the full purchase price allowing me to replace the Uwatec with a Suunto Vytec. Of course the Uwatec couldn't have been replaced for at least 30 days and at that point I had soured on it anyway.
I don't have anything against any LDS. Most of my gear purchases have been from various LDS. However, my unmitigated--and unconsidered--loyalty to my heretofore favorite LDS died when I realized that they were attempting to charge me twice as much for a new bc for my son as another LDS near me--and $200 more for a Scubapro MK25/S600 (which came with factory warranty) than DiveInn.
The almighty dollar? Yes, dollars I can use for actually diving.
Incidentally, I don't have either a BMW7 or a plasma tv, so if anyone wants to give me one, either with or without a warranty, I'll take it. The 3 year warranty on my car and the 1 year warranty on my tv have already run, so I pay for the repairs myself.