Meh, people are always going to complain when they see something they don't like or something they think doesn't work. Or more commonly they'll complain if that action is repeated or becomes the norm.
Some of the complaints are stupid but so I guess so is complaining about people complaining; it is a message board, after all.
As for the Buch/Chytil/ADA/etc., discussions, you can't really lump them all together. Some of it is fanboy-ism (He's my favorite prospect! He's an American/European! He isn't an American/European! I really like how he expresses himself on twitter!), some of it is the desire for the best players to play (a desire which is somehow rare in sports despite being the standard in literally every other possible industry, personally I'd rather the surgeon who is least likely to accidentally kill me or the car mechanic least likely to screw up my car over a replacement who always volunteers to work weekends and never comes in late) and some of it is just a concern about asset management. The level of stupid tends to vary by argument and poster.
At the end of the day coaches and goalies are always targets because they are easy targets, but really no one is really safe from getting grief. The Captain himself was regularly skewered on here during his second stint. It wasn't pretty.