Increasing my steps goal

Just tried it in the app and yes - 15K seems to be the upper limit. 
Makes one wonder - Why have such a low limit?

Because according to the W.H.O. the approximate number of steps required on a daily basis to maintain a healthy lifestyle is only 8000!
Personally, due to time restrictions and work, I find 10k a perfectly acceptable goal for day to day activity.

Seems very arbitrary. The software clearly supports a much, much higher limit for recording steps. Why not let users specify?

I do the opposite of you, and set my steps goal to a low number so I can celebrate multiple times per day. I bike a lot and it doesn't give me any steps (even though I know it's good for me) so I don't sweat it and I set my goal to 3,000.

It's kind of hard for me to imagine the lifestyle where you are exceeding 15,000 steps on a daily basis. That is 7.5 miles for the "average" person. If that is your routine, celebrate! If you need a higher goal, you could set it for 10,000 steps and try to hit that twice ;)

Yep, I did realise I could do that, and I aim for 20,000 (other lifestyle choices are available). 15,000 is still an arbitrarily low maximum, just as 3000 is an arbitrarily low minimum one. Why impose a limit at all when it's only displaying a percentage?