Arguments ad homenim don't have a place here, but I understand remarks like that have a history in Apple discussions. I will say that I am a lead plaintiff in a suit against Apple regarding hardware quality, so I am at least as qualified to criticize or defend them as you are.

The seal does matter for notebooks. I've repaired Lenovo and Dell books because they had inexplicable junk inside. Although a laptop can't usually survive total submersion or liquid poured on top, there are situations where keeping the bottom and sides sealed is helpful. This can also be achieved with rubber and some other techniques, but either it's thicker (another tradeoff that buyers don't want to make, for whatever reason) requires more complex manufacturing (which affects quality in other ways, or price--more tradeoffs.)

There are definitely thermal issues with MBPs in regards to performance and comfort, but no common ones that affect the glue. I welcome correction here, but if heat improved repairability so readily, we'd see that technique recommended and applied more often.

Edit: I saw your comment was flagged dead. I didn't do that. I vouched for it to restore it.