4-6 shows a season?! What the hell? Get off your lazy asses and make some TV, you tea drinkin', lift riding, brolley carrying fops!
6 episodes of Peep Show is not enough!
Yes it is. American TV shows are often too long. Dexter gets it about right with 12 episodes. A lot of shows that are 20-25 episodes in length contain a lot of padding unless they have a good arc. Ideas get stale, the actors & writers get fed up quicker.
A good series will leave you satisfied with what you've seen, and always wanting more. Peep Show has had multiple seasons, which is pretty good for a series on Channel 4. TV has limited funding here. Channel 4 is a commercial channel, but has been struggling financially for years. The Beeb is a monster, and could never commission a 20+ episode season, as it's public money they use, and would come at the detriment of its other programming - it's struggling anyway after wasting its money on numerous things other than programming.
Also, we don't have the same seasons as you. There's no breaks at 'fall', or whatever you guys call it - there's no need to have an unecessary break in a weekly formula. The clamour for ratings is far less cut-throat and competitive than US TV. Even the very worse shows are practically never cancelled in mid-season like some of yours.
I like having TV series run to 20+ episodes when it's done well, but there's no denying even the best series out there have padding, and lose their way at times.