I noticed every time I edit my answer it makes related question bump up on the question list. Isn't it bad? It would lead to situation where many PMSE members will use it to draw attention.
While it is true that editing a question or answer does bump it up to the top of the "Active" list, you do not need to worry about users abusing this too much. There is a specific number of edits that the system will allow before it automatically converts the content to Community Wiki.
Once content is converted to Community Wiki, the community owns it, and no more reputation can be gained from any subsequent upvotes.
As a result, it's in everyone's best interests to really make those edits count.
- Fix all spelling and grammar errors.
- Add reference links you intend to include.
- Add necessary whitespace and any formatting.
- Thoroughly review the preview before submitting.
Following the above points will help you make the most of your edits.
The bumping is useful in this case, to churn the sediment so we can find both treasures and trash.
Also, if edits were not bumped, edits would not get visibility; if someone went on an editing spree and vandalized a bunch of posts -- nobody would know. Putting it on the front page means the changes get vetted by the community.