I'm not so sure I would agree with that. Yeah, they have had some quality issues in the past (bad transmission coolers, CVT failures, faulty catalysts), but they've also brought us amazing engines like the SR20DET, RB25/26, the VQ V6 (designed in the early 1990s and still in mass production today) and its offshoot, the thoroughly insane VR38DETT that powers the GT-R. Not to mention the V8 they designed for racing but never used, the plans for which were purchased by McLaren and used (with some changes) to power every car they've built since the MP4-12C.
Given Nissan's recent/current product line (minus the GT-R), it's easy to forget that they can produce some pretty amazing stuff when they set their minds to it.