Why would my "dream team" work for me?

[Pasha Gorky]

Hello. I'll make this post an introduction, as well as my first question. 

I consider myself a beginner, despite being a landlord for close to 15 years now. I purchased a 1 bedroom condo for myself after moving out of my parents house, and then started renting it out when I moved in with my girlfriend (now my wife). Hindsight is always 20/20, and I realized I missed a very large opportunity in 2008 to purchase at least a few condos in that area for under $100,000 that could easily rent for $1,200. 

I am trying to learn as much as I can. I've attended a webinar , read "Rich Dad Poor Dad" book and currently reading the "BRRRR" book. Both of those books talk about having a dream team. You need a realtor, a contractor, etc.

Here's my question:
Why would a realtor who finds an amazing deal want to share it with me, instead of buying it for themselves?
Why would a contractor not want to buy that run down house and fix it themselves for the purpose of renting of flipping?