speed

Why do the puzzles have to be "speed"?  Why not just make them harder as we solve them and then step up when we do?  The speed part intimidates me and I don't give my best stuff when I am looking at a clock.  I know,  games are timed but not this fast.  And,  I am a "fun player".  I  play with friends and I just like to learn on my own schedule.  An example of my problem is that I was 1300 at one point and now I am under 1100.  And, there is no way I am rated 1300 on any real life numbers so why push me? Thank you, Dennis

Remember that you are given a minimum of +5 points whenever you solve a puzzle correctly.  It was set up that way so you can work puzzles as slowly as you want and still climb puzzle rating appropriately.

Also, remember that puzzle rating is completely different compared to bullet, blitz, and rapid ratings; if you do puzzles regularly, your puzzle rating should be much higher compared to the others.

Isn't +1 the lower bound of the rating gain?

It won't be a " fair " play without the speed limit. Players can just use a chess engine to analyze the position and always solve the puzzles correctly without any effort. 

Exactly! My puzzle rating is > 2200 but my blitz rating is just 800

The speed incentivises players for finding moves more quickly. In most circumstances, a player who completes a puzzle in 20 seconds is able to see the lines which a player who completes a puzzle in 5 minutes has calculated.

As with other systems of scoring, this may not always be the best approach all the time (the 20 second player might be very lucky to miss a potential trap completely while the 5 minute player has seen and calculated the trap thoroughly). However, adding some element of speed in solving puzzles is a fair approach in ensuring that players do not take way too long over a puzzle.

In the other site you train tactics on (which of course I know which website), there is a "mixed" timing control category, probably suitable for you. Maybe you are already training using that control.