Even if you're a one person studio, there is no excuse for releasing a game to masses of people without rigorous testing. When bugs slip through however, the least you can do is quickly look into it and let the reporting player know you're doing so. Players appreciate being listened to; and they appreciate prompt bug fixes at least as much.
I believe my full-time software development job enstilled a culture of user respect and immediacy into me. All of my games have an outlet for users to report bugs; on mobile versions I have a button that lets users e-mail me. On Steam I monitor the discussion threads, and on GameJolt and Kongregate there are user comments. Typically every reported item, whether a bug or suggestion, goes into a list I maintain along with the contact information of who submitted it.
I'll always let the bug submitter know when I've started looking into an issue. Sometimes on Steam I'll request to add them to my friends list because I need real-time discussion to better understand the bug. Doing so is always a big help in cases where I cannot duplicate it.
I try to fix critical bugs immediately. Non-critical bugs tend to get fixed promptly, and suggestions get done eventually if I think I'll get a reasonable ROI on them. Every so often when I post update news I'll also post a list of changes that I plan on making in the future to keep players coming back and to let them know I'm listening.
After all this, I have to say the reception from my player base has been very warm. I can't please everyone but read some of these snippets I've received from the Steam discussion groups and over e-mail:
"Thanks for working on it!"
"Its good now, thx."
"Thanks for your response. I honestly thought you were another developer that just put out a game and skipped, but you proved me wrong :)"
"WOW! You are awesome. Thank you for fixing the plunger issue. Much better in every way now."
Where am I going with all this? The importance of handling bug reports and responding to user concerns is obvious, but I think it deserves to go in the spotlight every so often. When users report bugs or say bad things about your game, they almost always do so because they care about your game and they want a better experience out of it.