Not really. They're used when there is a reason, such as someone who is expected to be there having a history of firearms violations, being possibly armed at the time or prior violent law enforcement contacts etc. No knock warrants in particular need justification for a judge to sign off on it. I think they probably are overused to an extent but it's got less to do with "hey we have an armored truck lets drive it into that marijuana grow house!" and more to do with departments going above and beyond to make sure they aren't getting sued after the fact for not being prepared for something and something goes wrong.
I'll give you an anecdotal example of my experience to illustrate what I mean. Lets say I want to go make suspect contact and search at a house on a sexual assault case I'm working. Prior to doing that, I have to run a complete criminal history on the suspect, run the address for any prior calls for service, try to identify everyone who might also be in the house, run criminal history on all of them, write a search/arrest warrant and get a judge to sign off on it, if I want it to be a night service or special entry type case I have to outline why in the warrant and the judge has to sign off on that part too, write an Operations Plan that is generally 8-10 pages long and involves listing all the facts of the case, all of the personnel who will be involved, list what vehicles they will be responding in, what their role will be once on scene, identify the nearest hospitals, local or state agencies that will be notified, then that Ops Plan has to be approved by my sergeant, then the lieutenant, then the captain before finally getting an okay to move forward. I'll spend about a week working up all of that for what will in all likelihood be about 45 minutes of absolutely nothing out of the ordinary happening.
Now, if at some point in all of that it's determined that the suspect or someone else at the house has prior violent crimes/firearms arrests or there is some information that someone there will be armed then everything screeches to a halt and they assign it as a SWAT entry for some later date and the process starts all over again.
Granted not every department is the same and there are plenty of fuck ups but it's silly to suggest that all cops are just running around doing crazy shit with no justification and no oversight for even minor things.