If I have amps to build I don't build pedals. If I have time to spare I make pedals. Making amps is more fun but more expensive.
I only build a pedal if there is a chance I will actually use it. Although I sometimes build a pedal as a request from a friend. My favourite thing is to find an overdrive I like which I think is almost perfect (for my particular use) and try to improve it or at least make it suit me better. It's not easy so I stumble around and almost give up, email Chuck, find out how to do it properly, ignore half of what he said through bloody-mindedness and because I'm stupid, realise that was a mistake, go back to Chuck's suggestions and then change it some more.
Sometimes I end up with a great pedal which may not suit everyone but which fills a need for me. I love it when Chuck says things like "R11, 13, 15 and 18 do nothing so leave then out." I love simplifying things.
Sometimes I'll build a pedal because it got good reviews or a friend suggests I try it. There are usually things I like and don't like about the circuit. For example I play Gretsches a lot and Filter'tron pickups can be fussy about OD because usually ODs are tuned for PAFs or Fender single coils. So ODs can sound fuzzy with Filter'trons and I would prefer a tight low end which twangs. Some ODs sound almost good with a Gretsch so I try to make them work better.
The other thing I like to do is add a bass pot to an OD. I think all ODs should have a bass pot. I think the KoT sounds ok but man it could use more low end. The Nobels OD sounds good but really needs a bass pot to reduce bass in some situations. Recently I found that the Protein Blue sounded excellent even with a Gretsch but I would have preferred it had a bass pot. So with Chuck's help I made one - it was ridiculously difficult but I have ended up with something which works for me extremely well - it doesn't sound exactly like a Protein Blue any more but has morphed into something else which works well for me.
So this is a very long way of saying no, I generally only build something if I think I will use it.