I'd offer you the any of the following (all of which apply to me):

• Because a new year, along with reminding people how much weight they put on eating Quality Street for most of December, also reminds them to sort out household maintenance projects that have been hanging around.
• Because some people are new to the area and don't know any reliable local tradespeople.
• Because some people put value in personal recommendation from recent customers.
• Because asking for recommendations encourages support of reliable local businesses which often thrive on word of mouth.
  

That's not to say that meaty debate on issues of the day should cease just because I need to sort out some rising damp but I'd hope they could happily co-exist on the forum.