As a new re-entrant to the vinyl realm, I have purchased some 500+ LP's over the past 2 years, mostly used Ebay and private collection jazz from the 50's thru 70's and some early 80's reissues (never go beyond 84 unless your sure it wasn't digitally remastered) I would estimated that less than 5% of everything I have purchased used has any noise (other than the original tape hiss which has been edited out of the digital version along with the soundstage, detail, dynamics etc.). I usually discard or replace any record with even a slight scratch unless very rare. You need, of course, to buy from reputable sellers and buy near mint to very good + records but most stuff is this quality even on Ebay because you can't sell crap for much. (But be prepared to pay well for quality)
If you are getting more noise than this, then record vacuming and cartridge quality (as noted by many other posters) is the issue. You can construct a cheap effective record vac yourself (search the archives) so there is no excuse for poor cleaning. Later you can go for an expensive commercial version if needed.
As a final note, I recently had a party at my home where I played my jazz records to a dumbfounded audience that had never heard decent vinyl. Their expectation was, like yours, that pop and crackle is just a necessary byproduct of vinyl. Their comments went way beyond the absence of this to obsessing over the detail and soundstage they had never realized was possible!
