The first thing I did was set up a google group for my friends. There are about 20 memebers in it and we share stuff between each other by email occasionally but also make plans.
The second thing I learned was never to entice people or make plans, but simply to announce plans. I'd email the group:
"I'm going hiking at Franconia Notch this weekend if anyone is interested. Leaving from my house around 10AM Saturday."
That's it. No waiting for replys, no waiting on people at all. If you want to come with me you'll be around at 10AM Saturday or you won't.
There's no frustration if its only me going, as I intended to go alone, and if anyone wants to come along then that's a pleasant surprise. But I won't base my activity schedule around waiting for them.
Surprisingly, since I started doing this, more people seem to come along. Motivation is contagious, I think, and it seems the thought of someone else already 100% committed to doing something makes it easier in the minds of others to commit themselves.
So make it easy for your friends. This way they don't feel guilty or obligated one way or the other, which is a huge relief for some personality types.
Later, I made a second google group for announcing house dinners, and now regularly 5-15 people show up every wednesday and we cook and eat together.
This is also a great way to get dates: you don't "ask" them on a date, you merely invite them to go on a date that you'd already planned. It works much the same way as you prescribe. You're actually implying: "I'm going to go do something cool with or without you, and this is my invitation for you to join me _if you wish_."
Additionally, you can't be stood up if you never solidify your plans to revolve solely around one other person.
Don't invite someone out "sometime". Propose having dinner this Friday at 8 pm. Or better, dinner this Friday at 8 pm at Chez Whatever.
If they don't like Chez Whatever, you can negotiate on this point. Or maybe 8:30 pm is better.
Anything other than a clean reason for declination, including the proverbial "Perhaps another time", is "no". Well... You might still follow up to be sure. Again, with a specific proposal.
I also like the idea of a sort of "non-date". I'm going to be doing some (cool to me, at least -- I'll be having fun) stuff. Want to join in?
If you're enjoying yourself, you're probably going to be a lot more attractive, anyway.
Specifically in the context of hiking, I've always told people who are interested in backpacking with me - if you wouldn't do this alone, you probably won't enjoy it even with a group.
As someone else mentioned, motivation is contagious.
You can then touch base with folks to find out what works and doesn't. So using the GP example you can inform folks you're hiking on Saturday a 10AM or something, and after a few of these you may find someone who expressed an interesting in hiking has never shown up, and you can check in with them. "Hey the hikes have been going great, would love to see you some time so we could hike together. Is there something that would make it easier for you to attend?" And you might get "ok my kids play soccer on Saturdays" or "I'm swamped with house projects" or something else.
If there is something you can try, like alternately going on Sundays or early morning weekdays, then try that. Sometimes it helps, sometimes it doesn't.
Life's too short to fart around with trying to find those extra few people. If you join a league, not only will you get your match fixes on a more regular basis, you'll have a broader pool to select from if you do try and set up something ad-hoc.
Seriously though, I understand what you are saying. Some people - men especially - seem to forget that there isn't much chance that there are scouts for premiership teams in the stands, because there isn't anyone in the stands at all.
There are rec leagues and co-ed leagues that are significantly more geared to people having a good time and not thinking they are the city's version of Messi. Seek those out. Also see if you can play in a Master's league (there are often 1-2 spots allowed, and often no age restrictions on keepers)
There are services like "FaltaUno.com" (one player missing :) ) that are trying to solve that problem !!!
Many people have just followed all their lives and that's what they like to do.
working out what works for you is just fine. go for it.
but using pseudo-psychology to put down people you don't understand is not so cool. there are plenty of valid reasons people don't want to do what you do (one may be to avoid passive-aggressive snarks like this...)
You leave the frustrating "let's do this together" phase and go into the "I'm doing this, I'll be happy if you join in!" phase, which is so much better.
My theory is that if you give the impression that you won't do it alone, it means you are not so sure about it and the project inspires less confidence.
Of course there are things you just can't do alone, but you can start alone and see who joins.
I strongly agree with the OP because it's a major shift in one's life. Very precious.