Out of millions of perfectly running Samsung devices, its very much possible that a very small fraction (~5-10%) would not be very long lasting or maybe defective. So a few bad experiences does not make Samsung bad. They do offer warranty for most of their products after all.
I also have few bad experiences with Samsung products, but i will never blame Samsung specifically for it. Samsung is one of the very top brands with highest quality standard products.
Majority of bad experiences occured with our own negligence, because we did not follow manufacturers guidelines properly.