Hearthpwn deck builder does not allow decks that have more than 30 cards, but does allow decks that have fewer than 30. This creates a problem for those of us trying to explore valid decks, and there doesn't seem to be a filter to limit to specific number of cards (usually 30, perhaps less for some brawls might be useful too).
To see how this problem manifests, start a search for decks of a certain class, then sort by dust from lowest to highest. The first 20 pages or so will be full of 0-dust decks or decks costing less than 400 dust. Opening any of them up will show decks with barely any cards in them. None of the filters help, neither Standard, nor Wild, nor Constructed factor in the card limit. The individual count limit filters in the drop-down on the bottom are tied to specific expansions. Could we get something like a "Full Deck" or "Deck needs at least ## cards" filter?
Using the "Show Constructed Only" filter eliminated a lot of them - I see brawl decks being a common occurrence on the list without it, and that mode ends up with a lot of weird deck building rules so that's an easy explanation.
It looks like the other few decks I see are people either encountering some form of error (and not reporting it =( ) or misuse of the deckbuilder and not submitting any cards at all (I don't see any decks with cards between 0 and 30). It may be worth us not allowing 0 card decks to help stomp this out. It also probably wouldn't be a bad idea for us to go through and delete some of these decks with no cards and no descriptions. I'll see if any of our mods are up to the challenge should they have some time.
I agree that having a filter for 30 card decks would ultimately be a good addition. In the meantime, Since most decks should at least have one common or free card in them, you could try using those filters by setting the boxes to  and . That would eliminate 0 card decks completely.
You could try it with  and  in the Basic or Classic set filters as well.
I'll look into getting this implemented so we can push it out. I can't give you an ETA right now though, so, soon (tm).
Not a problem, I want to get the most out of my experience here too and yes I am still missing common classics as of now.
I'm just guessing but it seems like you guys post anything that anyone saves? I can tell you from experience that I did not notice the favorite decks button for a few days and saved at least one copy of a deck already listed.
Another possibility is to have decks default to private rather than public since many of these were basically throw-away experiments by the creators. I often use deck builder to store my old decks that I have no room for ingame or incomplete theorycraft that may not be useful to others. The good/fun decks will still be shared (changed to public), but the one-off throwaway ones will not pollute global search results.