Yes, but the flaw in this argument (I think) is that you are implying that critical hits are to be relied upon to beat specific pokemon (Sigilyph) or strategies (Baton Pass). This is not the case - there are plenty of viable ways of dealing with these threats (Perish Song and Tricking Choice items immediately comes to mind, though there are others). This means that a critical hit is only ever hax - it's saving your butt when you haven't prepared for a threat (or dealt with it) properly. If Sigilyph gets to +6, that's on you; you should have built you're team to deal with it better, or played around it better. If you're relying on the crit to beat you're opponent's Sigilyph (just as an example), then you're relying on hax (or luck) to win in a situation where either:This is legit why we need critical hits to balance stuff out. Cosmic Power, Barrier, and bulky Calm Mind/Bulk Up users would be impossible to take down after a few boosts, simply because they are turning would be KOs into not KOs. It means that you won't lose 100% of the time because you got unlucky and you missed that one hit and that one Pokemon is just powering through you due to it. Its suprisingly easy to get stuff like Sigilyph and Baton Pass chains to work if the critical hit does not become a factor, and those two things, along with other annoyances, just become imposible to beat way too quickly.
Critical hits really do save games, even if they are incredibly annoying oftentimes.
-You're opponent has outplayed you or;
-You haven't prepared properly for a threat
Thus, crits should not bypass defense boosts as it (essentially) steals wins from players that should have won the match. There really isn't an excuse for letting something like Sigilyph get to +6. Or +3 for that matter.
That's just my feelings anyway.