you have different dynamics. the EU's imm philosophy is, well, relaxed, towards canadians.

then you have the US where you have officers who work for CBP as a CAREER, unlike CBSA where it's a step up for a 20-something to a job with the mounties. so you'll inevitably get more trained and experienced officers with CBP, and a trained and experience officer realizes that 99% of the people they see are compliant and not a threat.
and then you deal with CBP officers at a pre-clearance, which is GRAVY for the CBP officers because they don't need to carry anything on their belt (no guns, no cuffs, nothing, except maybe the remote car starter when it's -40c), they don't have to do arrests because CBSA or the police will do that for them. they also get paid VERY well (almost double their salary working back home) because they're considered government agents performing government tasks abroad, so therefore, they get "danger pay" and "living expense" pay. so combine the additional pay with fewer tasks, not to mention a flight schedule that is very predictable, and the officers who get selected for that are very senior and very well respected, you will get CBP officers who not only experienced and professional, but in a good mood.

then CBSA officers work for an agency that is flawed at so many levels, with co-workers who were originally hired to count heads of cattle or sit behind a window doing paperwork, with tons of new recruits, and a corporate culture of "don't rock the boat, do as you are told, don't ask questions, don't try doing anything differently, and everything will be fine", combined with a very poor public image (people see rev canada in a higher light than our border law enforcers according to that globe & mail survey a year ago or so), you have officials here who are idiots.

Interesting, you find that granting a foreign government the right to your fingerprints and background information less intrusive than a verbal question from a BSO? I prefer the "know your rights" thing a lot more than the "how is that appropriate?" line.

Remember, you are ENTITLED admittance into Canada without obstruction if you are a Canadian citizen and they have no reasonable doubt that you are Canadian. They cannot restrict that RIGHT from you. You can enter into Canada with nothing more than a "I am a Canadian citizen, I would like to seek re-admittance here". However, your GOODS are subject to search under ANY circumstances. They do not need cause or ANYTHING. (in fact, the RCMP uses that government right to get BSOs to perform intelligence gathering on suspected criminals/organized crime members/etc.) So remember that when you are at primary and secondary. They can't ask you anything about your-self, but they certainly can ask you about your-stuff. It still doesn't mean you have to answer, but answering may mitigate enforcement action on their part. However, they can't ask you what you do for a living, who pays your bills, how much income you earn, or if you have a criminal record under any circumstances (although you will most likely "be in the system" for the latter). If you're asked those questions, get the badge number and report it to the superintendent, chief, and your MP. That's a huge violation of your rights. A police officer that encounters you on the street has no right to ask you those questions, and a BSO definitely does not either.

Sometimes the personal stuff will bridge into the goods stuff, so feel free to ask for clarification as to why they need that information. They could be guising it as a customs question when really they are going to write it down and send it to CSIS & the RCMP as per their request (or the BSO can fire it off to the CBSA intelligence division at their own choosing). Your goods are 0 or 1, legal or illegal, they don't need you to tell them where you got it or how you got it. Only answer questions pertaining to your goods if it will mitigate yourself from sanctioning (eg. "I previously imported these jeans" "I acquired this lawfully from a gift shop"). Majority of customs seizures in Canada are made because the officer managed to twist the arm of the client enough to make that client confess. If they need to twist your arm, it's because they lack proof (normally, it's the receipt). If they want to seize stuff from you, they wouldn't need your testimony. If you're complaint, you don't need to say anything, although saying "I was in SFO on a 4 day vacation with the wife and I got this coffee from the food store" is of a much greater cost-benefit-ratio than saying "f-you, here's my luggage, i'll be sitting over there reading chateline", as much as you are legally entitled to do it.

Remember, your duty under the law is to present your self in order to verify your identity. Once there is no question that you are in fact the person named on that document and that you are in fact a Canadian citizen, your only duty from therein is to present your goods. PRESENT your goods, not PRESENT AND EXPLAIN your goods. In theory, you can leave your bags at secondary for them to search and you can walk out the port if you so choose. They can't stop you unless they have concerns about goods on or about your body. As a Canadian, you are only accountable in helping the BSO verify your identity and citizenship and presenting your goods.