They are having teething issues, which is bound to happen with any new rolling stock.
Generally, the reliability of any fleet of equipment can be graphed as a bell curve, with lower reliability as it enters service, increasing to high reliability as the equipment becomes better known and the processes for maintaining it become settled, and then dropping back down to a lower value as the equipment ages.
Anyone who feels that they are "lemons" is simply being too hasty with their pronouncements. It will take time before we really know how good or bad the equipment is.
And for the record, if you look at older copies of the equipment being used elsewhere - for instance, Amtrak Midwest out of Chicago - the locos have proven to be far, far more reliable than the older ones they replaced.
Dan