My thoughts:
*Too much tomato. The flavors are probably drowning in it
*Chili powder is a weird thing to put in salsa
*Jalapeno is not optional (unless replacing it with another variety of chili)
*Skip the garlic powder for real garlic
All in all there are lots better salsas out there. This one has an advantage of being fast and made primarily with shelf stable ingredients. Truly Mexican is a great introductory book for Mexican cookery and has a whole section on different kinds of salsas.
EDIT: formatting
Tired of salsa?! There are so many different ways to make salsa I have a hard time believing this. What ingredients have you tried?
For starters, check out Roberto Santabanez. Specifically, this book: http://www.amazon.com/Truly-Mexican-Essential-Techniques-Authentic/dp/0470499559/ref=sr_1_2?s=books&ie=UTF8&qid=1436111653&sr=1-2.
Even if you've already made 1/2 the recipes in that book, it should give you enough variety to last a while.
I mean, I've got a cookbook written by a Mexican chef that includes a guac recipe containing mayo.